{"timestamp":"2024-02-27T14:30:40.812518Z","id":"CVE-2021-46925","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","programFiles":["net/smc/smc.h","net/smc/smc_cdc.c","net/smc/smc_cdc.h","net/smc/smc_core.c","net/smc/smc_ib.c","net/smc/smc_ib.h","net/smc/smc_wr.c","net/smc/smc_wr.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"5f08318f617b05b6ee389d8bd174c7af921ebf19","lessThan":"e8a5988a85c719ce7205cb00dcf0716dcf611332","versionType":"git","status":"affected"},{"version":"5f08318f617b05b6ee389d8bd174c7af921ebf19","lessThan":"b85f751d71ae8e2a15e9bda98852ea9af35282eb","versionType":"git","status":"affected"},{"version":"5f08318f617b05b6ee389d8bd174c7af921ebf19","lessThan":"349d43127dac00c15231e8ffbcaabd70f7b0e544","versionType":"git","status":"affected"}]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","programFiles":["net/smc/smc.h","net/smc/smc_cdc.c","net/smc/smc_cdc.h","net/smc/smc_core.c","net/smc/smc_ib.c","net/smc/smc_ib.h","net/smc/smc_wr.c","net/smc/smc_wr.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"4.11","status":"affected"},{"version":"0","lessThan":"4.11","versionType":"semver","status":"unaffected"},{"version":"5.10.90","lessThanOrEqual":"5.10.*","versionType":"semver","status":"unaffected"},{"version":"5.15.13","lessThanOrEqual":"5.15.*","versionType":"semver","status":"unaffected"},{"version":"5.16","lessThanOrEqual":"*","versionType":"original_commit_for_fix","status":"unaffected"}]}]

https://git.kernel.org/stable/c/349d43127dac00c15231e8ffbcaabd70f7b0e544

https://git.kernel.org/stable/c/b85f751d71ae8e2a15e9bda98852ea9af35282eb

https://git.kernel.org/stable/c/e8a5988a85c719ce7205cb00dcf0716dcf611332

CISA-ADP AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA-ADP CWE-362

NIST AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

NIST CWE-362

OR
     *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.11.0 up to (excluding) 5.10.90
     *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11.0 up to (excluding) 5.15.13

https://git.kernel.org/stable/c/349d43127dac00c15231e8ffbcaabd70f7b0e544 No Types Assigned

https://git.kernel.org/stable/c/349d43127dac00c15231e8ffbcaabd70f7b0e544 Patch

https://git.kernel.org/stable/c/b85f751d71ae8e2a15e9bda98852ea9af35282eb No Types Assigned

https://git.kernel.org/stable/c/b85f751d71ae8e2a15e9bda98852ea9af35282eb Patch

https://git.kernel.org/stable/c/e8a5988a85c719ce7205cb00dcf0716dcf611332 No Types Assigned

https://git.kernel.org/stable/c/e8a5988a85c719ce7205cb00dcf0716dcf611332 Patch

In the Linux kernel, the following vulnerability has been resolved:

net/smc: fix kernel panic caused by race of smc_sock

A crash occurs when smc_cdc_tx_handler() tries to access smc_sock
but smc_release() has already freed it.

[ 4570.695099] BUG: unable to handle page fault for address: 000000002eae9e88
[ 4570.696048] #PF: supervisor write access in kernel mode
[ 4570.696728] #PF: error_code(0x0002) - not-present page
[ 4570.697401] PGD 0 P4D 0
[ 4570.697716] Oops: 0002 [#1] PREEMPT SMP NOPTI
[ 4570.698228] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.16.0-rc4+ #111
[ 4570.699013] Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/0
[ 4570.699933] RIP: 0010:_raw_spin_lock+0x1a/0x30
<...>
[ 4570.711446] Call Trace:
[ 4570.711746]  <IRQ>
[ 4570.711992]  smc_cdc_tx_handler+0x41/0xc0
[ 4570.712470]  smc_wr_tx_tasklet_fn+0x213/0x560
[ 4570.712981]  ? smc_cdc_tx_dismisser+0x10/0x10
[ 4570.713489]  tasklet_action_common.isra.17+0x66/0x140
[ 4570.714083]  __do_softirq+0x123/0x2f4
[ 4570.714521]  irq_exit_rcu+0xc4/0xf0
[ 4570.714934]  common_interrupt+0xba/0xe0

Though smc_cdc_tx_handler() checked the existence of smc connection,
smc_release() may have already dismissed and released the smc socket
before smc_cdc_tx_handler() further visits it.

smc_cdc_tx_handler()           |smc_release()
if (!conn)                     |
                               |
                               |smc_cdc_tx_dismiss_slots()
                               |      smc_cdc_tx_dismisser()
                               |
                               |sock_put(&smc->sk) <- last sock_put,
                               |                      smc_sock freed
bh_lock_sock(&smc->sk) (panic) |

To make sure we won't receive any CDC messages after we free the
smc_sock, add a refcount on the smc_connection for inflight CDC
message(posted to the QP but haven't received related CQE), and
don't release the smc_connection until all the inflight CDC messages
haven been done, for both success or failed ones.

Using refcount on CDC messa

Linux https://git.kernel.org/stable/c/349d43127dac00c15231e8ffbcaabd70f7b0e544 [No types assigned]

Linux https://git.kernel.org/stable/c/b85f751d71ae8e2a15e9bda98852ea9af35282eb [No types assigned]

Linux https://git.kernel.org/stable/c/e8a5988a85c719ce7205cb00dcf0716dcf611332 [No types assigned]