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.
Affected products
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – 35a22117839602bb52283de08894c5a7dde92420
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – 5d27d2ffe487df89ce28fda0410eafa05dbe03a0
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – 89f6fbe0033c942cb790ffd53ca93a45eeaf1c91
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – dcd90f42a33e4220385f27b515183d0c91b2fc4a
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – 94d286fa5eedc550d42bcb9c85416af8f77736ff
- Linux / Linuxa6a6fe27bab48f0d09a64b051e7bde432fcae081 – a3fdd924d88c30b9f488636ce0e4696012cf5511
- Linux / Linux5.18 – 5.18
- Linux / Linux0 – 5.18
- Linux / Linux6.1.176 – 6.1.*
- Linux / Linux6.6.143 – 6.6.*
- Linux / Linux6.12.94 – 6.12.*
- Linux / Linux6.18.36 – 6.18.*
- Linux / Linux7.0.13 – 7.0.*
- Linux / Linux7.1 – *
References
- MISChttps://git.kernel.org/stable/c/35a22117839602bb52283de08894c5a7dde92420
- MISChttps://git.kernel.org/stable/c/5d27d2ffe487df89ce28fda0410eafa05dbe03a0
- MISChttps://git.kernel.org/stable/c/89f6fbe0033c942cb790ffd53ca93a45eeaf1c91
- MISChttps://git.kernel.org/stable/c/dcd90f42a33e4220385f27b515183d0c91b2fc4a
- MISChttps://git.kernel.org/stable/c/94d286fa5eedc550d42bcb9c85416af8f77736ff
- MISChttps://git.kernel.org/stable/c/a3fdd924d88c30b9f488636ce0e4696012cf5511