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2017-03-16list: introduce list_first_entry_or_nullJiri Pirko
commit 6d7581e62f8be462440d7b22c6361f7c9fa4902b upstream. non-rcu variant of list_first_or_null_rcu Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16can: Fix kernel panic at security_sock_rcv_skbEric Dumazet
[ Upstream commit f1712c73714088a7252d276a57126d56c7d37e64 ] Zhang Yanmin reported crashes [1] and provided a patch adding a synchronize_rcu() call in can_rx_unregister() The main problem seems that the sockets themselves are not RCU protected. If CAN uses RCU for delivery, then sockets should be freed only after one RCU grace period. Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's ease stable backports with the following fix instead. [1] BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0 Call Trace: <IRQ> [<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60 [<ffffffff81d55771>] sk_filter+0x41/0x210 [<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0 [<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0 [<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370 [<ffffffff81f07af9>] can_receive+0xd9/0x120 [<ffffffff81f07beb>] can_rcv+0xab/0x100 [<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0 [<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0 [<ffffffff81d37f67>] process_backlog+0x127/0x280 [<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0 [<ffffffff810c88d4>] __do_softirq+0x184/0x440 [<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30 <EOI> [<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40 [<ffffffff810c8bed>] do_softirq+0x1d/0x20 [<ffffffff81d30085>] netif_rx_ni+0xe5/0x110 [<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520 [<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230 [<ffffffff810e3baf>] process_one_work+0x24f/0x670 [<ffffffff810e44ed>] worker_thread+0x9d/0x6f0 [<ffffffff810e4450>] ? rescuer_thread+0x480/0x480 [<ffffffff810ebafc>] kthread+0x12c/0x150 [<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70 Reported-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16net: avoid sk_forward_alloc overflowsEric Dumazet
[ Upstream commit 20c64d5cd5a2bdcdc8982a06cb05e5e1bd851a3d ] A malicious TCP receiver, sending SACK, can force the sender to split skbs in write queue and increase its memory usage. Then, when socket is closed and its write queue purged, we might overflow sk_forward_alloc (It becomes negative) sk_mem_reclaim() does nothing in this case, and more than 2GB are leaked from TCP perspective (tcp_memory_allocated is not changed) Then warnings trigger from inet_sock_destruct() and sk_stream_kill_queues() seeing a not zero sk_forward_alloc All TCP stack can be stuck because TCP is under memory pressure. A simple fix is to preemptively reclaim from sk_mem_uncharge(). This makes sure a socket wont have more than 2 MB forward allocated, after burst and idle period. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16net: fix sk_mem_reclaim_partial()Eric Dumazet
commit 1a24e04e4b50939daa3041682b38b82c896ca438 upstream. sk_mem_reclaim_partial() goal is to ensure each socket has one SK_MEM_QUANTUM forward allocation. This is needed both for performance and better handling of memory pressure situations in follow up patches. SK_MEM_QUANTUM is currently a page, but might be reduced to 4096 bytes as some arches have 64KB pages. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Keep using atomic_long_sub() directly, not sk_memory_allocated_sub() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16net/sock: Add sock_efree() functionBen Hutchings
Extracted from commit 62bccb8cdb69 ("net-timestamp: Make the clone operation stand-alone from phy timestamping"). Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16netlabel: out of bound access in cipso_v4_validate()Eric Dumazet
commit d71b7896886345c53ef1d84bda2bc758554f5d61 upstream. syzkaller found another out of bound access in ip_options_compile(), or more exactly in cipso_v4_validate() Fixes: 20e2a8648596 ("cipso: handle CIPSO options correctly when NetLabel is disabled") Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paul Moore <paul@paul-moore.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16gro: Disable frag0 optimization on IPv6 ext headersHerbert Xu
commit 57ea52a865144aedbcd619ee0081155e658b6f7d upstream. The GRO fast path caches the frag0 address. This address becomes invalid if frag0 is modified by pskb_may_pull or its variants. So whenever that happens we must disable the frag0 optimization. This is usually done through the combination of gro_header_hard and gro_header_slow, however, the IPv6 extension header path did the pulling directly and would continue to use the GRO fast path incorrectly. This patch fixes it by disabling the fast path when we enter the IPv6 extension header path. Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address") Reported-by: Slava Shwartsman <slavash@mellanox.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-03-16hotplug: Make register and unregister notifier API symmetricMichal Hocko
commit 777c6e0daebb3fcefbbd6f620410a946b07ef6d0 upstream. Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its notifiers when HOTPLUG_CPU=y while the registration might succeed even when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap might keep a stale notifier on the list on the manual clean up during the pool tear down and thus corrupt the list. Resulting in the following [ 144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78 [ 144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40 <snipped> [ 145.122628] Call Trace: [ 145.125086] [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20 [ 145.131350] [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400 [ 145.137268] [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300 [ 145.143188] [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10 [ 145.149018] [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30 [ 145.154940] [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0 [ 145.160511] [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20 [ 145.167035] [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0 [ 145.172694] [<ffffffffa290848d>] module_attr_store+0x1d/0x30 [ 145.178443] [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70 [ 145.183925] [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180 [ 145.189761] [<ffffffffa2a99248>] __vfs_write+0x18/0x40 [ 145.194982] [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0 [ 145.200122] [<ffffffffa2a9a732>] SyS_write+0x52/0xa0 [ 145.205177] [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17 This can be even triggered manually by changing /sys/module/zswap/parameters/compressor multiple times. Fix this issue by making unregister APIs symmetric to the register so there are no surprises. Fixes: 47e627bc8c9a ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU") Reported-and-tested-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: - The lockless (__-prefixed) variants don't exist - Keep definition of cpu_notify_nofail() conditional on CONFIG_HOTPLUG_CPU] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23tcp: take care of truncations done by sk_filter()Eric Dumazet
commit ac6e780070e30e4c35bd395acfe9191e6268bdd3 upstream. With syzkaller help, Marco Grassi found a bug in TCP stack, crashing in tcp_collapse() Root cause is that sk_filter() can truncate the incoming skb, but TCP stack was not really expecting this to happen. It probably was expecting a simple DROP or ACCEPT behavior. We first need to make sure no part of TCP header could be removed. Then we need to adjust TCP_SKB_CB(skb)->end_seq Many thanks to syzkaller team and Marco for giving us a reproducer. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Marco Grassi <marco.gra@gmail.com> Reported-by: Vladis Dronov <vdronov@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23dccp: limit sk_filter trim to payloadWillem de Bruijn
commit 4f0c40d94461cfd23893a17335b2ab78ecb333c8 upstream. Dccp verifies packet integrity, including length, at initial rcv in dccp_invalid_packet, later pulls headers in dccp_enqueue_skb. A call to sk_filter in-between can cause __skb_pull to wrap skb->len. skb_copy_datagram_msg interprets this as a negative value, so (correctly) fails with EFAULT. The negative length is reported in ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close. Introduce an sk_receive_skb variant that caps how small a filter program can trim packets, and call this in dccp with the header length. Excessively trimmed packets are now processed normally and queued for reception as 0B payloads. Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23rose: limit sk_filter trim to payloadWillem de Bruijn
commit f4979fcea7fd36d8e2f556abef86f80e0d5af1ba upstream. Sockets can have a filter program attached that drops or trims incoming packets based on the filter program return value. Rose requires data packets to have at least ROSE_MIN_LEN bytes. It verifies this on arrival in rose_route_frame and unconditionally pulls the bytes in rose_recvmsg. The filter can trim packets to below this value in-between, causing pull to fail, leaving the partial header at the time of skb_copy_datagram_msg. Place a lower bound on the size to which sk_filter may trim packets by introducing sk_filter_trim_cap and call this for rose packets. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23net: Add __sock_queue_rcv_skb()Ben Hutchings
Extraxcted from commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac "udp: remove headers from UDP packets before queueing". Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23lockdep: Silence warning if CONFIG_LOCKDEP isn't setPaul Bolle
commit 5cd3f5affad2109fd1458aab3f6216f2181e26ea upstream. Since commit c9a4962881929df7f1ef6e63e1b9da304faca4dd ("nfsd: make client_lock per net") compiling nfs4state.o without CONFIG_LOCKDEP set, triggers this GCC warning: fs/nfsd/nfs4state.c: In function ‘free_client’: fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable] The cause of that warning is that lockdep_assert_held() compiles away if CONFIG_LOCKDEP is not set. Silence this warning by using the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP is not set. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: J. Bruce Fields <bfields@redhat.com> Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@x61.thuisdomein Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2017-02-23can: raw: raw_setsockopt: limit number of can_filter that can be setMarc Kleine-Budde
commit 332b05ca7a438f857c61a3c21a88489a21532364 upstream. This patch adds a check to limit the number of can_filters that can be set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER are not prevented resulting in a warning. Reference: https://lkml.org/lkml/2016/12/2/230 Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20posix_acl: Clear SGID bit when setting file permissionsJan Kara
commit 073931017b49d9458aa351605b43a7e34598caef upstream. When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> [bwh: Backported to 3.2: - Drop changes to ceph, f2fs, hfsplus, orangefs - Use capable() instead of capable_wrt_inode_uidgid() - Update ext3 and generic_acl.c as well - In gfs2, jfs, and xfs, take care to avoid leaking the allocated ACL if posix_acl_update_mode() determines it's not needed - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20fs: Give dentry to inode_change_ok() instead of inodeJan Kara
commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.2: - Drop changes to f2fs, lustre, orangefs, overlayfs - Adjust filenames, context - In nfsd, pass dentry to nfsd_sanitize_attrs() - In xfs, pass dentry to xfs_change_file_space(), xfs_set_mode(), xfs_setattr_nonsize(), and xfs_setattr_size() - Update ext3 as well - Mark pohmelfs as BROKEN; it's long dead upstream] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_routeNikolay Aleksandrov
commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 upstream. Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid instead of the previous dst_pid which was copied from in_skb's portid. Since the skb is new the portid is 0 at that point so the packets are sent to the kernel and we get scheduling while atomic or a deadlock (depending on where it happens) by trying to acquire rtnl two times. Also since this is RTM_GETROUTE, it can be triggered by a normal user. Here's the sleeping while atomic trace: [ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 [ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0 [ 7858.212881] 2 locks held by swapper/0/0: [ 7858.213013] #0: (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350 [ 7858.213422] #1: (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130 [ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179 [ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 7858.214108] 0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000 [ 7858.214412] ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e [ 7858.214716] 000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f [ 7858.215251] Call Trace: [ 7858.215412] <IRQ> [<ffffffff813a7804>] dump_stack+0x85/0xc1 [ 7858.215662] [<ffffffff810a4a72>] ___might_sleep+0x192/0x250 [ 7858.215868] [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100 [ 7858.216072] [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0 [ 7858.216279] [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460 [ 7858.216487] [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40 [ 7858.216687] [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260 [ 7858.216900] [<ffffffff81573c70>] rtnl_unicast+0x20/0x30 [ 7858.217128] [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0 [ 7858.217351] [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130 [ 7858.217581] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217785] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217990] [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350 [ 7858.218192] [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350 [ 7858.218415] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.218656] [<ffffffff810fde10>] run_timer_softirq+0x260/0x640 [ 7858.218865] [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f [ 7858.219068] [<ffffffff816637c8>] __do_softirq+0xe8/0x54f [ 7858.219269] [<ffffffff8107a948>] irq_exit+0xb8/0xc0 [ 7858.219463] [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50 [ 7858.219678] [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0 [ 7858.219897] <EOI> [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10 [ 7858.220165] [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10 [ 7858.220373] [<ffffffff810298e3>] default_idle+0x23/0x190 [ 7858.220574] [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20 [ 7858.220790] [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60 [ 7858.221016] [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0 [ 7858.221257] [<ffffffff8164f995>] rest_init+0x135/0x140 [ 7858.221469] [<ffffffff81f83014>] start_kernel+0x50e/0x51b [ 7858.221670] [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120 [ 7858.221894] [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c [ 7858.222113] [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Use 'pid' instead of 'portid' where necessary - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20can: dev: fix deadlock reported after bus-offSergei Miroshnichenko
commit 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 upstream. A timer was used to restart after the bus-off state, leading to a relatively large can_restart() executed in an interrupt context, which in turn sets up pinctrl. When this happens during system boot, there is a high probability of grabbing the pinctrl_list_mutex, which is locked already by the probe() of other device, making the kernel suspect a deadlock condition [1]. To resolve this issue, the restart_timer is replaced by a delayed work. [1] https://github.com/victronenergy/venus/issues/24 Signed-off-by: Sergei Miroshnichenko <sergeimir@emcraft.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20asm-generic: make get_user() clear the destination on errorsAl Viro
commit 9ad18b75c2f6e4a78ce204e79f37781f8815c0fa upstream. both for access_ok() failures and for faults halfway through Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20asm-generic: make copy_from_user() zero the destination properlyAl Viro
commit 2545e5da080b4839dd859e3b09343a884f6ab0e3 upstream. ... in all cases, including the failing access_ok() Note that some architectures using asm-generic/uaccess.h have __copy_from_user() not zeroing the tail on failure halfway through. This variant works either way. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20tcp: fix use after free in tcp_xmit_retransmit_queue()Eric Dumazet
commit bb1fceca22492109be12640d49f5ea5a544c6bb4 upstream. When tcp_sendmsg() allocates a fresh and empty skb, it puts it at the tail of the write queue using tcp_add_write_queue_tail() Then it attempts to copy user data into this fresh skb. If the copy fails, we undo the work and remove the fresh skb. Unfortunately, this undo lacks the change done to tp->highest_sack and we can leave a dangling pointer (to a freed skb) Later, tcp_xmit_retransmit_queue() can dereference this pointer and access freed memory. For regular kernels where memory is not unmapped, this might cause SACK bugs because tcp_highest_sack_seq() is buggy, returning garbage instead of tp->snd_nxt, but with various debug features like CONFIG_DEBUG_PAGEALLOC, this can crash the kernel. This bug was found by Marco Grassi thanks to syzkaller. Fixes: 6859d49475d4 ("[TCP]: Abstract tp->highest_sack accessing & point to next skb") Reported-by: Marco Grassi <marco.gra@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20Input: i8042 - break load dependency between atkbd/psmouse and i8042Dmitry Torokhov
commit 4097461897df91041382ff6fcd2bfa7ee6b2448c upstream. As explained in 1407814240-4275-1-git-send-email-decui@microsoft.com we have a hard load dependency between i8042 and atkbd which prevents keyboard from working on Gen2 Hyper-V VMs. > hyperv_keyboard invokes serio_interrupt(), which needs a valid serio > driver like atkbd.c. atkbd.c depends on libps2.c because it invokes > ps2_command(). libps2.c depends on i8042.c because it invokes > i8042_check_port_owner(). As a result, hyperv_keyboard actually > depends on i8042.c. > > For a Generation 2 Hyper-V VM (meaning no i8042 device emulated), if a > Linux VM (like Arch Linux) happens to configure CONFIG_SERIO_I8042=m > rather than =y, atkbd.ko can't load because i8042.ko can't load(due to > no i8042 device emulated) and finally hyperv_keyboard can't work and > the user can't input: https://bugs.archlinux.org/task/39820 > (Ubuntu/RHEL/SUSE aren't affected since they use CONFIG_SERIO_I8042=y) To break the dependency we move away from using i8042_check_port_owner() and instead allow serio port owner specify a mutex that clients should use to serialize PS/2 command stream. Reported-by: Mark Laws <mdl@60hz.org> Tested-by: Mark Laws <mdl@60hz.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-11-20x86/quirks: Add early quirk to reset Apple AirPort cardLukas Wunner
commit abb2bafd295fe962bbadc329dbfb2146457283ac upstream. The EFI firmware on Macs contains a full-fledged network stack for downloading OS X images from osrecovery.apple.com. Unfortunately on Macs introduced 2011 and 2012, EFI brings up the Broadcom 4331 wireless card on every boot and leaves it enabled even after ExitBootServices has been called. The card continues to assert its IRQ line, causing spurious interrupts if the IRQ is shared. It also corrupts memory by DMAing received packets, allowing for remote code execution over the air. This only stops when a driver is loaded for the wireless card, which may be never if the driver is not installed or blacklisted. The issue seems to be constrained to the Broadcom 4331. Chris Milsted has verified that the newer Broadcom 4360 built into the MacBookPro11,3 (2013/2014) does not exhibit this behaviour. The chances that Apple will ever supply a firmware fix for the older machines appear to be zero. The solution is to reset the card on boot by writing to a reset bit in its mmio space. This must be done as an early quirk and not as a plain vanilla PCI quirk to successfully combat memory corruption by DMAed packets: Matthew Garrett found out in 2012 that the packets are written to EfiBootServicesData memory (http://mjg59.dreamwidth.org/11235.html). This type of memory is made available to the page allocator by efi_free_boot_services(). Plain vanilla PCI quirks run much later, in subsys initcall level. In-between a time window would be open for memory corruption. Random crashes occurring in this time window and attributed to DMAed packets have indeed been observed in the wild by Chris Bainbridge. When Matthew Garrett analyzed the memory corruption issue in 2012, he sought to fix it with a grub quirk which transitions the card to D3hot: http://git.savannah.gnu.org/cgit/grub.git/commit/?id=9d34bb85da56 This approach does not help users with other bootloaders and while it may prevent DMAed packets, it does not cure the spurious interrupts emanating from the card. Unfortunately the card's mmio space is inaccessible in D3hot, so to reset it, we have to undo the effect of Matthew's grub patch and transition the card back to D0. Note that the quirk takes a few shortcuts to reduce the amount of code: The size of BAR 0 and the location of the PM capability is identical on all affected machines and therefore hardcoded. Only the address of BAR 0 differs between models. Also, it is assumed that the BCMA core currently mapped is the 802.11 core. The EFI driver seems to always take care of this. Michael Büsch, Bjorn Helgaas and Matt Fleming contributed feedback towards finding the best solution to this problem. The following should be a comprehensive list of affected models: iMac13,1 2012 21.5" [Root Port 00:1c.3 = 8086:1e16] iMac13,2 2012 27" [Root Port 00:1c.3 = 8086:1e16] Macmini5,1 2011 i5 2.3 GHz [Root Port 00:1c.1 = 8086:1c12] Macmini5,2 2011 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1c12] Macmini5,3 2011 i7 2.0 GHz [Root Port 00:1c.1 = 8086:1c12] Macmini6,1 2012 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1e12] Macmini6,2 2012 i7 2.3 GHz [Root Port 00:1c.1 = 8086:1e12] MacBookPro8,1 2011 13" [Root Port 00:1c.1 = 8086:1c12] MacBookPro8,2 2011 15" [Root Port 00:1c.1 = 8086:1c12] MacBookPro8,3 2011 17" [Root Port 00:1c.1 = 8086:1c12] MacBookPro9,1 2012 15" [Root Port 00:1c.1 = 8086:1e12] MacBookPro9,2 2012 13" [Root Port 00:1c.1 = 8086:1e12] MacBookPro10,1 2012 15" [Root Port 00:1c.1 = 8086:1e12] MacBookPro10,2 2012 13" [Root Port 00:1c.1 = 8086:1e12] For posterity, spurious interrupts caused by the Broadcom 4331 wireless card resulted in splats like this (stacktrace omitted): irq 17: nobody cared (try booting with the "irqpoll" option) handlers: [<ffffffff81374370>] pcie_isr [<ffffffffc0704550>] sdhci_irq [sdhci] threaded [<ffffffffc07013c0>] sdhci_thread_irq [sdhci] [<ffffffffc0a0b960>] azx_interrupt [snd_hda_codec] Disabling IRQ #17 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79301 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111781 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=728916 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=895951#c16 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1009819 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1098621 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1149632#c5 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1279130 Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1332732 Tested-by: Konstantin Simanov <k.simanov@stlk.ru> # [MacBookPro8,1] Tested-by: Lukas Wunner <lukas@wunner.de> # [MacBookPro9,1] Tested-by: Bryan Paradis <bryan.paradis@gmail.com> # [MacBookPro9,2] Tested-by: Andrew Worsley <amworsley@gmail.com> # [MacBookPro10,1] Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> # [MacBookPro10,2] Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Rafał Miłecki <zajec5@gmail.com> Acked-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chris Milsted <cmilsted@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Michael Buesch <m@bues.ch> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: b43-dev@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: linux-wireless@vger.kernel.org Link: http://lkml.kernel.org/r/48d0972ac82a53d460e5fce77a07b2560db95203.1465690253.git.lukas@wunner.de [ Did minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: - early_ioremap() is declared in <asm/io.h> not <asm/early_ioremap.h> - Add definition of BCMA_RESET_ST - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-10-20mm, gup: close FOLL MAP_PRIVATE raceMichal Hocko
commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 upstream. faultin_page drops FOLL_WRITE after the page fault handler did the CoW and then we retry follow_page_mask to get our CoWed page. This is racy, however because the page might have been unmapped by that time and so we would have to do a page fault again, this time without CoW. This would cause the page cache corruption for FOLL_FORCE on MAP_PRIVATE read only mappings with obvious consequences. This is an ancient bug that was actually already fixed once by Linus eleven years ago in commit 4ceb5db9757a ("Fix get_user_pages() race for write access") but that was then undone due to problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug") because s390 didn't have proper dirty pte tracking until abf09bed3cce ("s390/mm: implement software dirty bits"). This wasn't a problem at the time as pointed out by Hugh Dickins because madvise relied on mmap_sem for write up until 0a27a14a6292 ("mm: madvise avoid exclusive mmap_sem") but since then we can race with madvise which can unmap the fresh COWed page or with KSM and corrupt the content of the shared page. This patch is based on the Linus' approach to not clear FOLL_WRITE after the CoW page fault (aka VM_FAULT_WRITE) but instead introduces FOLL_COW to note this fact. The flag is then rechecked during follow_pfn_pte to enforce the page fault again if we do not see the CoWed page. Linus was suggesting to check pte_dirty again as s390 is OK now. But that would make backporting to some old kernels harder. So instead let's just make sure that vm_normal_page sees a pure anonymous page. This would guarantee we are seeing a real CoW page. Introduce can_follow_write_pte which checks both pte_write and falls back to PageAnon on forced write faults which passed CoW already. Thanks to Hugh to point out that a special care has to be taken for KSM pages because our COWed page might have been merged with a KSM one and keep its PageAnon flag. Fixes: 0a27a14a6292 ("mm: madvise avoid exclusive mmap_sem") Reported-by: Phil "not Paul" Oester <kernel@linuxace.com> Disclosed-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Michal Hocko <mhocko@suse.com> [bwh: Backported to 3.2: - Adjust filename, context, indentation - The 'no_page' exit path in follow_page() is different, so open-code the cleanup - Delete a now-unused label] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22fs: limit filesystem stacking depthMiklos Szeredi
commit 69c433ed2ecd2d3264efd7afec4439524b319121 upstream. Add a simple read-only counter to super_block that indicates how deep this is in the stack of filesystems. Previously ecryptfs was the only stackable filesystem and it explicitly disallowed multiple layers of itself. Overlayfs, however, can be stacked recursively and also may be stacked on top of ecryptfs or vice versa. To limit the kernel stack usage we must limit the depth of the filesystem stack. Initially the limit is set to 2. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> [bwh: Backported to 3.2: - Drop changes to overlayfs - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22etherdevice: introduce help function eth_zero_addr()Duan Jiong
commit 6d57e9078e880a3dd232d579f42ac437a8f1ef7b upstream. a lot of code has either the memset or an inefficient copy from a static array that contains the all-zeros Ethernet address. Introduce help function eth_zero_addr() to fill an address with all zeros, making the code clearer and allowing us to get rid of some constant arrays. Signed-off-by: Duan Jiong <djduanjiong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22mm: Export migrate_page_move_mapping and migrate_page_copyRichard Weinberger
commit 1118dce773d84f39ebd51a9fe7261f9169cb056e upstream. Export these symbols such that UBIFS can implement ->migratepage. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Christoph Hellwig <hch@lst.de> [bwh: Backported to 3.2: also change migrate_page_move_mapping() from static to extern, done as part of an earlier commit upstream] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-08-22sunrpc: Update RPCBIND_MAXNETIDLENChuck Lever
commit 4b9c7f9db9a003f5c342184dc4401c1b7f2efb39 upstream. Commit 176e21ee2ec8 ("SUNRPC: Support for RPC over AF_LOCAL transports") added a 5-character netid, but did not bump RPCBIND_MAXNETIDLEN from 4 to 5. Fixes: 176e21ee2ec8 ("SUNRPC: Support for RPC over AF_LOCAL ...") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15Minimal fix-up of bad hashing behavior of hash_64()Linus Torvalds
commit 689de1d6ca95b3b5bd8ee446863bf81a4883ea25 upstream. This is a fairly minimal fixup to the horribly bad behavior of hash_64() with certain input patterns. In particular, because the multiplicative value used for the 64-bit hash was intentionally bit-sparse (so that the multiply could be done with shifts and adds on architectures without hardware multipliers), some bits did not get spread out very much. In particular, certain fairly common bit ranges in the input (roughly bits 12-20: commonly with the most information in them when you hash things like byte offsets in files or memory that have block factors that mean that the low bits are often zero) would not necessarily show up much in the result. There's a bigger patch-series brewing to fix up things more completely, but this is the fairly minimal fix for the 64-bit hashing problem. It simply picks a much better constant multiplier, spreading the bits out a lot better. NOTE! For 32-bit architectures, the bad old hash_64() remains the same for now, since 64-bit multiplies are expensive. The bigger hashing cleanup will replace the 32-bit case with something better. The new constants were picked by George Spelvin who wrote that bigger cleanup series. I just picked out the constants and part of the comment from that series. Cc: George Spelvin <linux@horizon.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15Make hash_64() use a 64-bit multiply when appropriateLinus Torvalds
commit 23d0db76ffa13ffb95229946e4648568c3c29db5 upstream. The hash_64() function historically does the multiply by the GOLDEN_RATIO_PRIME_64 number with explicit shifts and adds, because unlike the 32-bit case, gcc seems unable to turn the constant multiply into the more appropriate shift and adds when required. However, that means that we generate those shifts and adds even when the architecture has a fast multiplier, and could just do it better in hardware. Use the now-cleaned-up CONFIG_ARCH_HAS_FAST_MULTIPLIER (together with "is it a 64-bit architecture") to decide whether to use an integer multiply or the explicit sequence of shift/add instructions. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> [bwh: This has no immediate effect in 3.2 because nothing defines CONFIG_ARCH_HAS_FAST_MULTIPLIER. However the following fix removes that condition.]
2016-06-15IB/security: Restrict use of the write() interfaceJason Gunthorpe
commit e6bd18f57aad1a2d1ef40e646d03ed0f2515c9e3 upstream. The drivers/infiniband stack uses write() as a replacement for bi-directional ioctl(). This is not safe. There are ways to trigger write calls that result in the return structure that is normally written to user space being shunted off to user specified kernel memory instead. For the immediate repair, detect and deny suspicious accesses to the write API. For long term, update the user space libraries and the kernel API to something that doesn't present the same security vulnerabilities (likely a structured ioctl() interface). The impacted uAPI interfaces are generally only available if hardware from drivers/infiniband is installed in the system. Reported-by: Jann Horn <jann@thejh.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> [ Expanded check to all known write() entry points ] Signed-off-by: Doug Ledford <dledford@redhat.com> [bwh: Backported to 3.2: - Drop changes to hfi1 - include/rdma/ib.h didn't exist, so create it with the usual header guard and include it in drivers/infiniband/core/ucma.c - ipath_write() has the same problem, so add the same restriction there] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15mm: hugetlb: allow hugepages_supported to be architecture specificDominik Dingel
commit 2531c8cf56a640cd7d17057df8484e570716a450 upstream. s390 has a constant hugepage size, by setting HPAGE_SHIFT we also change e.g. the pageblock_order, which should be independent in respect to hugepage support. With this patch every architecture is free to define how to check for hugepage support. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15hugetlb: ensure hugepage access is denied if hugepages are not supportedNishanth Aravamudan
commit 457c1b27ed56ec472d202731b12417bff023594a upstream. Currently, I am seeing the following when I `mount -t hugetlbfs /none /dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`. I think it's related to the fact that hugetlbfs is properly not correctly setting itself up in this state?: Unable to handle kernel paging request for data at address 0x00000031 Faulting instruction address: 0xc000000000245710 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries .... In KVM guests on Power, in a guest not backed by hugepages, we see the following: AnonHugePages: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 64 kB HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages are not supported at boot-time, but this is only checked in hugetlb_init(). Extract the check to a helper function, and use it in a few relevant places. This does make hugetlbfs not supported (not registered at all) in this environment. I believe this is fine, as there are no valid hugepages and that won't change at runtime. [akpm@linux-foundation.org: use pr_info(), per Mel] [akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined] Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: - Drop changes to hugetlb_show_meminfo() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15USB: uas: Add a new NO_REPORT_LUNS quirkHans de Goede
commit 1363074667a6b7d0507527742ccd7bbed5e3ceaa upstream. Add a new NO_REPORT_LUNS quirk and set it for Seagate drives with an usb-id of: 0bc2:331a, as these will fail to respond to a REPORT_LUNS command. Reported-and-tested-by: David Webb <djw@noc.ac.uk> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: - Adjust context - Drop the UAS changes] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-06-15Revert "net: validate variable length ll headers"Ben Hutchings
This reverts commit b5518429e70cd783b8ca52335456172c1a0589f6, which was commit 2793a23aacbd754dbbb5cb75093deb7e4103bace upstream. It is pointless unless af_packet calls the new function. Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01net: validate variable length ll headersWillem de Bruijn
[ Upstream commit 2793a23aacbd754dbbb5cb75093deb7e4103bace ] Netdevice parameter hard_header_len is variously interpreted both as an upper and lower bound on link layer header length. The field is used as upper bound when reserving room at allocation, as lower bound when validating user input in PF_PACKET. Clarify the definition to be maximum header length. For validation of untrusted headers, add an optional validate member to header_ops. Allow bypassing of validation by passing CAP_SYS_RAWIO, for instance for deliberate testing of corrupt input. In this case, pad trailing bytes, as some device drivers expect completely initialized headers. See also http://comments.gmane.org/gmane.linux.network/401064 Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: net_device has inline comments instead of kernel-doc] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01net/ipv6: add sysctl option accept_ra_min_hop_limitHangbin Liu
[ Upstream commit 8013d1d7eafb0589ca766db6b74026f76b7f5cb4 ] Commit 6fd99094de2b ("ipv6: Don't reduce hop limit for an interface") disabled accept hop limit from RA if it is smaller than the current hop limit for security stuff. But this behavior kind of break the RFC definition. RFC 4861, 6.3.4. Processing Received Router Advertisements A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time, and Retrans Timer) may contain a value denoting that it is unspecified. In such cases, the parameter should be ignored and the host should continue using whatever value it is already using. If the received Cur Hop Limit value is non-zero, the host SHOULD set its CurHopLimit variable to the received value. So add sysctl option accept_ra_min_hop_limit to let user choose the minimum hop limit value they can accept from RA. And set default to 1 to meet RFC standards. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust filename, context - Number DEVCONF enumerators explicitly to match upstream] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01ipv6: update skb->csum when CE mark is propagatedEric Dumazet
[ Upstream commit 34ae6a1aa0540f0f781dd265366036355fdc8930 ] When a tunnel decapsulates the outer header, it has to comply with RFC 6080 and eventually propagate CE mark into inner header. It turns out IP6_ECN_set_ce() does not correctly update skb->csum for CHECKSUM_COMPLETE packets, triggering infamous "hw csum failure" messages and stack traces. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust context - Add skb argument to other callers of IP6_ECN_set_ce()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01fs/coredump: prevent fsuid=0 dumps into user-controlled directoriesJann Horn
commit 378c6520e7d29280f400ef2ceaf155c86f05a71a upstream. This commit fixes the following security hole affecting systems where all of the following conditions are fulfilled: - The fs.suid_dumpable sysctl is set to 2. - The kernel.core_pattern sysctl's value starts with "/". (Systems where kernel.core_pattern starts with "|/" are not affected.) - Unprivileged user namespace creation is permitted. (This is true on Linux >=3.8, but some distributions disallow it by default using a distro patch.) Under these conditions, if a program executes under secure exec rules, causing it to run with the SUID_DUMP_ROOT flag, then unshares its user namespace, changes its root directory and crashes, the coredump will be written using fsuid=0 and a path derived from kernel.core_pattern - but this path is interpreted relative to the root directory of the process, allowing the attacker to control where a coredump will be written with root privileges. To fix the security issue, always interpret core_pattern for dumps that are written under SUID_DUMP_ROOT relative to the root directory of init. Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01dm snapshot: disallow the COW and origin devices from being identicalDingXiang
commit 4df2bf466a9c9c92f40d27c4aa9120f4e8227bfc upstream. Otherwise loading a "snapshot" table using the same device for the origin and COW devices, e.g.: echo "0 20971520 snapshot 253:3 253:3 P 8" | dmsetup create snap will trigger: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 1958.979934] IP: [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1958.989655] PGD 0 [ 1958.991903] Oops: 0000 [#1] SMP ... [ 1959.059647] CPU: 9 PID: 3556 Comm: dmsetup Tainted: G IO 4.5.0-rc5.snitm+ #150 ... [ 1959.083517] task: ffff8800b9660c80 ti: ffff88032a954000 task.ti: ffff88032a954000 [ 1959.091865] RIP: 0010:[<ffffffffa040efba>] [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.104295] RSP: 0018:ffff88032a957b30 EFLAGS: 00010246 [ 1959.110219] RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000001 [ 1959.118180] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff880329334a00 [ 1959.126141] RBP: ffff88032a957b50 R08: 0000000000000000 R09: 0000000000000001 [ 1959.134102] R10: 000000000000000a R11: f000000000000000 R12: ffff880330884d80 [ 1959.142061] R13: 0000000000000008 R14: ffffc90001c13088 R15: ffff880330884d80 [ 1959.150021] FS: 00007f8926ba3840(0000) GS:ffff880333440000(0000) knlGS:0000000000000000 [ 1959.159047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1959.165456] CR2: 0000000000000098 CR3: 000000032f48b000 CR4: 00000000000006e0 [ 1959.173415] Stack: [ 1959.175656] ffffc90001c13040 ffff880329334a00 ffff880330884ed0 ffff88032a957bdc [ 1959.183946] ffff88032a957bb8 ffffffffa040f225 ffff880329334a30 ffff880300000000 [ 1959.192233] ffffffffa04133e0 ffff880329334b30 0000000830884d58 00000000569c58cf [ 1959.200521] Call Trace: [ 1959.203248] [<ffffffffa040f225>] dm_exception_store_create+0x1d5/0x240 [dm_snapshot] [ 1959.211986] [<ffffffffa040d310>] snapshot_ctr+0x140/0x630 [dm_snapshot] [ 1959.219469] [<ffffffffa0005c44>] ? dm_split_args+0x64/0x150 [dm_mod] [ 1959.226656] [<ffffffffa0005ea7>] dm_table_add_target+0x177/0x440 [dm_mod] [ 1959.234328] [<ffffffffa0009203>] table_load+0x143/0x370 [dm_mod] [ 1959.241129] [<ffffffffa00090c0>] ? retrieve_status+0x1b0/0x1b0 [dm_mod] [ 1959.248607] [<ffffffffa0009e35>] ctl_ioctl+0x255/0x4d0 [dm_mod] [ 1959.255307] [<ffffffff813304e2>] ? memzero_explicit+0x12/0x20 [ 1959.261816] [<ffffffffa000a0c3>] dm_ctl_ioctl+0x13/0x20 [dm_mod] [ 1959.268615] [<ffffffff81215eb6>] do_vfs_ioctl+0xa6/0x5c0 [ 1959.274637] [<ffffffff81120d2f>] ? __audit_syscall_entry+0xaf/0x100 [ 1959.281726] [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70 [ 1959.288814] [<ffffffff81216449>] SyS_ioctl+0x79/0x90 [ 1959.294450] [<ffffffff8167e4ae>] entry_SYSCALL_64_fastpath+0x12/0x71 ... [ 1959.323277] RIP [<ffffffffa040efba>] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.333090] RSP <ffff88032a957b30> [ 1959.336978] CR2: 0000000000000098 [ 1959.344121] ---[ end trace b049991ccad1169e ]--- Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1195899 Signed-off-by: Ding Xiang <dingxiang@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> [bwh: Backported to 3.2: the device path parsing code is rather different, but move it into dm_get_dev_t() anyway] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-05-01PCI: Disable IO/MEM decoding for devices with non-compliant BARsBjorn Helgaas
commit b84106b4e2290c081cdab521fa832596cdfea246 upstream. The PCI config header (first 64 bytes of each device's config space) is defined by the PCI spec so generic software can identify the device and manage its usage of I/O, memory, and IRQ resources. Some non-spec-compliant devices put registers other than BARs where the BARs should be. When the PCI core sizes these "BARs", the reads and writes it does may have unwanted side effects, and the "BAR" may appear to describe non-sensical address space. Add a flag bit to mark non-compliant devices so we don't touch their BARs. Turn off IO/MEM decoding to prevent the devices from consuming address space, since we can't read the BARs to find out what that address space would be. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Andi Kleen <ak@linux.intel.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01include/linux/poison.h: fix LIST_POISON{1,2} offsetVasily Kulikov
commit 8a5e5e02fc83aaf67053ab53b359af08c6c49aaf upstream. Poison pointer values should be small enough to find a room in non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space" is located starting from 0x0. Given unprivileged users cannot mmap anything below mmap_min_addr, it should be safe to use poison pointers lower than mmap_min_addr. The current poison pointer values of LIST_POISON{1,2} might be too big for mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu uses only 0x10000). There is little point to use such a big value given the "poison pointer space" below 1 MB is not yet exhausted. Changing it to a smaller value solves the problem for small mmap_min_addr setups. The values are suggested by Solar Designer: http://www.openwall.com/lists/oss-security/2015/05/02/6 Signed-off-by: Vasily Kulikov <segoon@openwall.com> Cc: Solar Designer <solar@openwall.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01mld, igmp: Fix reserved tailroom calculationBenjamin Poirier
commit 1837b2e2bcd23137766555a63867e649c0b637f0 upstream. The current reserved_tailroom calculation fails to take hlen and tlen into account. skb: [__hlen__|__data____________|__tlen___|__extra__] ^ ^ head skb_end_offset In this representation, hlen + data + tlen is the size passed to alloc_skb. "extra" is the extra space made available in __alloc_skb because of rounding up by kmalloc. We can reorder the representation like so: [__hlen__|__data____________|__extra__|__tlen___] ^ ^ head skb_end_offset The maximum space available for ip headers and payload without fragmentation is min(mtu, data + extra). Therefore, reserved_tailroom = data + extra + tlen - min(mtu, data + extra) = skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen) = skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen) Compare the second line to the current expression: reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset) and we can see that hlen and tlen are not taken into account. The min() in the third line can be expanded into: if mtu < skb_tailroom - tlen: reserved_tailroom = skb_tailroom - mtu else: reserved_tailroom = tlen Depending on hlen, tlen, mtu and the number of multicast address records, the current code may output skbs that have less tailroom than dev->needed_tailroom or it may output more skbs than needed because not all space available is used. Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs") Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01libata: Align ata_device's id on a cachelineHarvey Hunt
commit 4ee34ea3a12396f35b26d90a094c75db95080baa upstream. The id buffer in ata_device is a DMA target, but it isn't explicitly cacheline aligned. Due to this, adjacent fields can be overwritten with stale data from memory on non coherent architectures. As a result, the kernel is sometimes unable to communicate with an ATA device. Fix this by ensuring that the id buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f ("libata: align ap->sector_buf"). Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01tracing: Fix freak link error caused by branch tracerArnd Bergmann
commit b33c8ff4431a343561e2319f17c14286f2aa52e2 upstream. In my randconfig tests, I came across a bug that involves several components: * gcc-4.9 through at least 5.3 * CONFIG_GCOV_PROFILE_ALL enabling -fprofile-arcs for all files * CONFIG_PROFILE_ALL_BRANCHES overriding every if() * The optimized implementation of do_div() that tries to replace a library call with an division by multiplication * code in drivers/media/dvb-frontends/zl10353.c doing u32 adc_clock = 450560; /* 45.056 MHz */ if (state->config.adc_clock) adc_clock = state->config.adc_clock; do_div(value, adc_clock); In this case, gcc fails to determine whether the divisor in do_div() is __builtin_constant_p(). In particular, it concludes that __builtin_constant_p(adc_clock) is false, while __builtin_constant_p(!!adc_clock) is true. That in turn throws off the logic in do_div() that also uses __builtin_constant_p(), and instead of picking either the constant- optimized division, and the code in ilog2() that uses __builtin_constant_p() to figure out whether it knows the answer at compile time. The result is a link error from failing to find multiple symbols that should never have been called based on the __builtin_constant_p(): dvb-frontends/zl10353.c:138: undefined reference to `____ilog2_NaN' dvb-frontends/zl10353.c:138: undefined reference to `__aeabi_uldivmod' ERROR: "____ilog2_NaN" [drivers/media/dvb-frontends/zl10353.ko] undefined! ERROR: "__aeabi_uldivmod" [drivers/media/dvb-frontends/zl10353.ko] undefined! This patch avoids the problem by changing __trace_if() to check whether the condition is known at compile-time to be nonzero, rather than checking whether it is actually a constant. I see this one link error in roughly one out of 1600 randconfig builds on ARM, and the patch fixes all known instances. Link: http://lkml.kernel.org/r/1455312410-1058841-1-git-send-email-arnd@arndb.de Acked-by: Nicolas Pitre <nico@linaro.org> Fixes: ab3c9c686e22 ("branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01tracepoints: Do not trace when cpu is offlineSteven Rostedt (Red Hat)
commit f37755490fe9bf76f6ba1d8c6591745d3574a6a6 upstream. The tracepoint infrastructure uses RCU sched protection to enable and disable tracepoints safely. There are some instances where tracepoints are used in infrastructure code (like kfree()) that get called after a CPU is going offline, and perhaps when it is coming back online but hasn't been registered yet. This can probuce the following warning: [ INFO: suspicious RCU usage. ] 4.4.0-00006-g0fe53e8-dirty #34 Tainted: G S ------------------------------- include/trace/events/kmem.h:141 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/8/0. stack backtrace: CPU: 8 PID: 0 Comm: swapper/8 Tainted: G S 4.4.0-00006-g0fe53e8-dirty #34 Call Trace: [c0000005b76c78d0] [c0000000008b9540] .dump_stack+0x98/0xd4 (unreliable) [c0000005b76c7950] [c00000000010c898] .lockdep_rcu_suspicious+0x108/0x170 [c0000005b76c79e0] [c00000000029adc0] .kfree+0x390/0x440 [c0000005b76c7a80] [c000000000055f74] .destroy_context+0x44/0x100 [c0000005b76c7b00] [c0000000000934a0] .__mmdrop+0x60/0x150 [c0000005b76c7b90] [c0000000000e3ff0] .idle_task_exit+0x130/0x140 [c0000005b76c7c20] [c000000000075804] .pseries_mach_cpu_die+0x64/0x310 [c0000005b76c7cd0] [c000000000043e7c] .cpu_die+0x3c/0x60 [c0000005b76c7d40] [c0000000000188d8] .arch_cpu_idle_dead+0x28/0x40 [c0000005b76c7db0] [c000000000101e6c] .cpu_startup_entry+0x50c/0x560 [c0000005b76c7ed0] [c000000000043bd8] .start_secondary+0x328/0x360 [c0000005b76c7f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14 This warning is not a false positive either. RCU is not protecting code that is being executed while the CPU is offline. Instead of playing "whack-a-mole(TM)" and adding conditional statements to the tracepoints we find that are used in this instance, simply add a cpu_online() test to the tracepoint code where the tracepoint will be ignored if the CPU is offline. Use of raw_smp_processor_id() is fine, as there should never be a case where the tracepoint code goes from running on a CPU that is online and suddenly gets migrated to a CPU that is offline. Link: http://lkml.kernel.org/r/1455387773-4245-1-git-send-email-kda@linux-powerpc.org Reported-by: Denis Kirjanov <kda@linux-powerpc.org> Fixes: 97e1c18e8d17b ("tracing: Kernel Tracepoints") Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01libata: fix HDIO_GET_32BIT ioctlArnd Bergmann
commit 287e6611ab1eac76c2c5ebf6e345e04c80ca9c61 upstream. As reported by Soohoon Lee, the HDIO_GET_32BIT ioctl does not work correctly in compat mode with libata. I have investigated the issue further and found multiple problems that all appeared with the same commit that originally introduced HDIO_GET_32BIT handling in libata back in linux-2.6.8 and presumably also linux-2.4, as the code uses "copy_to_user(arg, &val, 1)" to copy a 'long' variable containing either 0 or 1 to user space. The problems with this are: * On big-endian machines, this will always write a zero because it stores the wrong byte into user space. * In compat mode, the upper three bytes of the variable are updated by the compat_hdio_ioctl() function, but they now contain uninitialized stack data. * The hdparm tool calling this ioctl uses a 'static long' variable to store the result. This means at least the upper bytes are initialized to zero, but calling another ioctl like HDIO_GET_MULTCOUNT would fill them with data that remains stale when the low byte is overwritten. Fortunately libata doesn't implement any of the affected ioctl commands, so this would only happen when we query both an IDE and an ATA device in the same command such as "hdparm -N -c /dev/hda /dev/sda" * The libata code for unknown reasons started using ATA_IOC_GET_IO32 and ATA_IOC_SET_IO32 as aliases for HDIO_GET_32BIT and HDIO_SET_32BIT, while the ioctl commands that were added later use the normal HDIO_* names. This is harmless but rather confusing. This addresses all four issues by changing the code to use put_user() on an 'unsigned long' variable in HDIO_GET_32BIT, like the IDE subsystem does, and by clarifying the names of the ioctl commands. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Soohoon Lee <Soohoon.Lee@f5.com> Tested-by: Soohoon Lee <Soohoon.Lee@f5.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01nfs: fix nfs_size_to_loff_tChristoph Hellwig
commit 50ab8ec74a153eb30db26529088bc57dd700b24c upstream. See http: //www.infradead.org/rpr.html X-Evolution-Source: 1451162204.2173.11@leira.trondhjem.org Content-Transfer-Encoding: 8bit Mime-Version: 1.0 We support OFFSET_MAX just fine, so don't round down below it. Also switch to using min_t to make the helper more readable. Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 433c92379d9c ("NFS: Clean up nfs_size_to_loff_t()") Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-04-01cfg80211/wext: fix message orderingJohannes Berg
commit cb150b9d23be6ee7f3a0fff29784f1c5b5ac514d upstream. Since cfg80211 frequently takes actions from its netdev notifier call, wireless extensions messages could still be ordered badly since the wext netdev notifier, since wext is built into the kernel, runs before the cfg80211 netdev notifier. For example, the following can happen: 5: wlan1: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff 5: wlan1: <BROADCAST,MULTICAST,UP> link/ether when setting the interface down causes the wext message. To also fix this, export the wireless_nlevent_flush() function and also call it from the cfg80211 notifier. Signed-off-by: Johannes Berg <johannes.berg@intel.com> [bwh: Backported to 3.2: - Add default case in cfg80211_netdev_notifier_call() which bypasses the added wireless_nlevent_flush() (added upstream by commit 6784c7db8d43 "cfg80211: change return value of notifier function") - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2016-02-27pipe: limit the per-user amount of pages allocated in pipesWilly Tarreau
commit 759c01142a5d0f364a462346168a56de28a80f52 upstream. On no-so-small systems, it is possible for a single process to cause an OOM condition by filling large pipes with data that are never read. A typical process filling 4000 pipes with 1 MB of data will use 4 GB of memory. On small systems it may be tricky to set the pipe max size to prevent this from happening. This patch makes it possible to enforce a per-user soft limit above which new pipes will be limited to a single page, effectively limiting them to 4 kB each, as well as a hard limit above which no new pipes may be created for this user. This has the effect of protecting the system against memory abuse without hurting other users, and still allowing pipes to work correctly though with less data at once. The limit are controlled by two new sysctls : pipe-user-pages-soft, and pipe-user-pages-hard. Both may be disabled by setting them to zero. The default soft limit allows the default number of FDs per process (1024) to create pipes of the default size (64kB), thus reaching a limit of 64MB before starting to create only smaller pipes. With 256 processes limited to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB = 1084 MB of memory allocated for a user. The hard limit is disabled by default to avoid breaking existing applications that make intensive use of pipes (eg: for splicing). Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-17 03:24:50 +0000