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authorD. Wythe <alibuda@linux.alibaba.com>2023-02-16 14:37:36 +0800
committerDavid S. Miller <davem@davemloft.net>2023-02-20 08:07:01 +0000
commite40b801b3603a8f90b46acbacdea3505c27f01c0 (patch)
treed46db1f9e794ac8616ec6d6f9c6ddf274ec840db /net/smc/af_smc.c
parentec35307e18ba8174e2a3f701956059f6a36f22fb (diff)
net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()
There is a certain chance to trigger the following panic: PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48" #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62 [exception RIP: ib_alloc_mr+19] RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc] #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc] #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc] The reason here is that when the server tries to create a second link, smc_llc_srv_add_link() has no protection and may add a new link to link group. This breaks the security environment protected by llc_conf_mutex. Fixes: 2d2209f20189 ("net/smc: first part of add link processing as SMC server") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/af_smc.c')
-rw-r--r--net/smc/af_smc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index e12d4fa5aece..d9413d43b104 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1826,8 +1826,10 @@ static int smcr_serv_conf_first_link(struct smc_sock *smc)
smc_llc_link_active(link);
smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
+ mutex_lock(&link->lgr->llc_conf_mutex);
/* initial contact - try to establish second link */
smc_llc_srv_add_link(link, NULL);
+ mutex_unlock(&link->lgr->llc_conf_mutex);
return 0;
}