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Fencer Vulns
no cvss —

CVE-2025-40357 json

net/smc: fix general protection fault in __smc_diag_dump

published 2025-12-16 10 mo ago modified 2026-10-14 26 d ago also EUVD-2025-203630

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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

net/smc: fix general protection fault in __smc_diag_dump

The syzbot report a crash:

Oops: general protection fault, probably for non-canonical address 0xfbd5a5d5a0000003: 0000 [#1] SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead4ead00000018-0xdead4ead0000001f] CPU: 1 UID: 0 PID: 6949 Comm: syz.0.335 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:smc_diag_msg_common_fill net/smc/smc_diag.c:44 [inline] RIP: 0010:__smc_diag_dump.constprop.0+0x3ca/0x2550 net/smc/smc_diag.c:89 Call Trace: <TASK> smc_diag_dump_proto+0x26d/0x420 net/smc/smc_diag.c:217 smc_diag_dump+0x27/0x90 net/smc/smc_diag.c:234 netlink_dump+0x539/0xd30 net/netlink/af_netlink.c:2327 __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2442 netlink_dump_start include/linux/netlink.h:341 [inline] smc_diag_handler_dump+0x1f9/0x240 net/smc/smc_diag.c:251 __sock_diag_cmd net/core/sock_diag.c:249 [inline] sock_diag_rcv_msg+0x438/0x790 net/core/sock_diag.c:285 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK>

The process like this:

(CPU1) | (CPU2) ---------------------------------|------------------------------- inet_create() | // init clcsock to NULL | sk = sk_alloc() | | // unexpectedly change clcsock | inet_init_csk_locks() | | // add sk to hash table | smc_inet_init_sock() | smc_sk_init() | smc_hash_sk() | | // traverse the hash table | smc_diag_dump_proto | __smc_diag_dump() | // visit wrong clcsock | smc_diag_msg_common_fill() // alloc clcsock | smc_create_clcsk | sock_create_kern |

With CONFIG_DEBUG_LOCK_ALLOC=y, the smc->clcsock is unexpectedly changed in inet_init_csk_locks(). The INET_PROTOSW_ICSK flag is no need by smc, just remove it.

After removing the INET_PROTOSW_ICSK flag, this patch alse revert commit 6fd27ea183c2 ("net/smc: fix lacks of icsk_syn_mss with IPPROTO_SMC") to avoid casting smc_sock to inet_connection_sock.

Patch / fix

  • Linux Linux 6.12.56, 6.17.6, 6.18
  • linux Debian 13 6.12.57-1
  • linux Debian 14 6.17.6-1

debian advisories DEBIAN-CVE-2025-40357

  • linux Ubuntu 25.10 6.17.0-14.14
  • linux-aws Ubuntu 25.10 6.17.0-1007.7
  • linux-gcp Ubuntu 25.10 6.17.0-1007.7
  • linux-azure Ubuntu 25.10 6.17.0-1008.8
  • linux-raspi Ubuntu 25.10 6.17.0-1008.8
  • linux-riscv Ubuntu 25.10 6.17.0-14.14.1
  • linux-oracle Ubuntu 25.10 6.17.0-1007.7
  • linux-aws-6.17 Ubuntu 24.04 LTS 6.17.0-1007.7~24.04.1

ubuntu advisories UBUNTU-CVE-2025-40357

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Linux Micro 6.2 6.12.0-160000.9.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.9.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.9.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.9.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.9.1.160000.2.6
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.9.1
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.9.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.9.1

suse advisories SUSE-SU-2026:20207-1SUSE-SU-2026:20220-1SUSE-SU-2026:20564-1SUSE-SU-2026:20228-1SUSE-SU-2026:0315-1SUSE-SU-2026:0281-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.9.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.9.1

opensuse advisories openSUSE-SU-2026:20145-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-40357 updated cvss 4.7

kernel: net/smc: fix general protection fault in __smc_diag_dump

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more Red Hat Enterprise Linux 10 kernel
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.