CVE-2026-53274: Linux kernel · net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS A logic flaw in __smc_setsockopt() allows a local unprivileged user to cause a Denial of Service (DoS) by holding the socket lock indefinitely. The function __smc_setsockopt() calls copy_from_sockptr() while holding lock_sock(sk). By passing a userfaultfd-monitored memory page (or FUSE-backed memory on systems where unprivileged userfaultfd is disabled) as the optval, an attacker can halt execution during the copy operation, keeping the lock held. Combined with asynchronous tear-down operations like shutdown(), this exhausts the kernel wq (kworkers) and triggers the hung task watchdog. [ 240.123456] INFO: task kworker/u8:2 blocked for more than 120 seconds. [ 240.123489] Call Trace: [ 240.123501] smc_shutdown+... [ 240.123512] lock_sock_nested+... This patch moves the user-space copy outside the lock_sock() critical section to prevent the issue.
References
- nvd.nist.gov/vuln/detail/CVE-2026-53274 (opens in a new tab)
- git.kernel.org/stable/c/35a22117839602bb52283de08894c5a7dde92420 (opens in a new tab)
- git.kernel.org/stable/c/5d27d2ffe487df89ce28fda0410eafa05dbe03a0 (opens in a new tab)
- git.kernel.org/stable/c/89f6fbe0033c942cb790ffd53ca93a45eeaf1c91 (opens in a new tab)
- git.kernel.org/stable/c/94d286fa5eedc550d42bcb9c85416af8f77736ff (opens in a new tab)
- git.kernel.org/stable/c/a3fdd924d88c30b9f488636ce0e4696012cf5511 (opens in a new tab)
- git.kernel.org/stable/c/dcd90f42a33e4220385f27b515183d0c91b2fc4a (opens in a new tab)