Description

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

net/smc: protect link down work from execute after lgr freed

link down work may be scheduled before lgr freed but execute
after lgr freed, which may result in crash. So it is need to
hold a reference before shedule link down work, and put the
reference after work executed or canceled.

The relevant crash call stack as follows:
list_del corruption. prev->next should be ffffb638c9c0fe20,
but was 0000000000000000
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:51!
invalid opcode: 0000 [#1] SMP NOPTI
CPU: 6 PID: 978112 Comm: kworker/6:119 Kdump: loaded Tainted: G #1
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 2221b89 04/01/2014
Workqueue: events smc_link_down_work [smc]
RIP: 0010:__list_del_entry_valid.cold+0x31/0x47
RSP: 0018:ffffb638c9c0fdd8 EFLAGS: 00010086
RAX: 0000000000000054 RBX: ffff942fb75e5128 RCX: 0000000000000000
RDX: ffff943520930aa0 RSI: ffff94352091fc80 RDI: ffff94352091fc80
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffb638c9c0fc38
R10: ffffb638c9c0fc30 R11: ffffffffa015eb28 R12: 0000000000000002
R13: ffffb638c9c0fe20 R14: 0000000000000001 R15: ffff942f9cd051c0
FS: 0000000000000000(0000) GS:ffff943520900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f25214000 CR3: 000000025fbae004 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000000000...

Classification

CVE ID: CVE-2024-56718

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/bec2f52866d511e94c1c37cd962e4382b1b1a299
https://git.kernel.org/stable/c/2627c3e8646932dfc7b9722c88c2e1ffcf7a9fb2
https://git.kernel.org/stable/c/841b1824750d3b8d1dc0a96b14db4418b952abbc
https://git.kernel.org/stable/c/2b33eb8f1b3e8c2f87cfdbc8cc117f6bdfabc6ec

Timeline