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authorIdo Schimmel <idosch@nvidia.com>2022-09-14 10:53:38 +0300
committerJakub Kicinski <kuba@kernel.org>2022-09-20 08:22:15 -0700
commitb07a9b26e2b1aa3711fd6935eccb08a463b1fb11 (patch)
treeb764464adf12f6c47dc4c98d8142c080dfa96471 /net
parentcf412ec333250cb82bafe57169204e14a9f1c2ac (diff)
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section
These functions expect to be called from RCU read-side critical section, but this only happens when invoked from the data path via ip{,6}_mr_input(). They can also be invoked from process context in response to user space adding a multicast route which resolves a cache entry with queued packets [1][2]. Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call paths. [1] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420 stack backtrace: CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ipmr_queue_xmit+0x135/0x1ab0 ip_mr_forward+0xe7b/0x13d0 ipmr_mfc_add+0x1a06/0x2ad0 ip_mroute_setsockopt+0x5c1/0x1420 do_ip_setsockopt+0x23d/0x37f0 ip_setsockopt+0x56/0x80 raw_setsockopt+0x219/0x290 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [2] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630 stack backtrace: CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ip6mr_forward2.isra.0+0xc9/0x1160 ip6_mr_forward+0xef0/0x13f0 ip6mr_mfc_add+0x1ff2/0x31f0 ip6_mroute_setsockopt+0x1825/0x2630 do_ipv6_setsockopt+0x462/0x4440 ipv6_setsockopt+0x105/0x140 rawv6_setsockopt+0xd8/0x690 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/ipmr.c2
-rw-r--r--net/ipv6/ip6mr.c5
2 files changed, 6 insertions, 1 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 73651d17e51f..e11d6b0b62b7 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1004,7 +1004,9 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
} else {
+ rcu_read_lock();
ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
+ rcu_read_unlock();
}
}
}
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index a9ba41648e36..858fd8a28b5b 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1028,8 +1028,11 @@ static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt,
((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE;
}
rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
- } else
+ } else {
+ rcu_read_lock();
ip6_mr_forward(net, mrt, skb->dev, skb, c);
+ rcu_read_unlock();
+ }
}
}