CVE-2026-53274 is a vulnerability in Linux Kernel
Published on June 25, 2026
net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS
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.
Products Associated with CVE-2026-53274
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Affected Versions
Linux:- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below 35a22117839602bb52283de08894c5a7dde92420 is affected.
- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below 5d27d2ffe487df89ce28fda0410eafa05dbe03a0 is affected.
- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below 89f6fbe0033c942cb790ffd53ca93a45eeaf1c91 is affected.
- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below dcd90f42a33e4220385f27b515183d0c91b2fc4a is affected.
- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below 94d286fa5eedc550d42bcb9c85416af8f77736ff is affected.
- Version a6a6fe27bab48f0d09a64b051e7bde432fcae081 and below a3fdd924d88c30b9f488636ce0e4696012cf5511 is affected.
- Version 5.18 is affected.
- Before 5.18 is unaffected.
- Version 6.1.176, <= 6.1.* is unaffected.
- Version 6.6.143, <= 6.6.* is unaffected.
- Version 6.12.94, <= 6.12.* is unaffected.
- Version 6.18.36, <= 6.18.* is unaffected.
- Version 7.0.13, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.