{"id":"CVE-2026-53274","title":"net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS\n\nA logic flaw in __smc_setsockopt() allows a local unprivileged user to\ncause a Denial of Service…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 35a22117839602bb52283de08894c5a7dde92420","Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 5d27d2ffe487df89ce28fda0410eafa05dbe03a0","Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 89f6fbe0033c942cb790ffd53ca93a45eeaf1c91","Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < dcd90f42a33e4220385f27b515183d0c91b2fc4a","Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 94d286fa5eedc550d42bcb9c85416af8f77736ff","Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < a3fdd924d88c30b9f488636ce0e4696012cf5511","Linux 5.18"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:24:48.310624Z"},"published":"2026-06-25","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:34:17.070Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53274","references":[{"url":"https://git.kernel.org/stable/c/35a22117839602bb52283de08894c5a7dde92420"},{"url":"https://git.kernel.org/stable/c/5d27d2ffe487df89ce28fda0410eafa05dbe03a0"},{"url":"https://git.kernel.org/stable/c/89f6fbe0033c942cb790ffd53ca93a45eeaf1c91"},{"url":"https://git.kernel.org/stable/c/dcd90f42a33e4220385f27b515183d0c91b2fc4a"},{"url":"https://git.kernel.org/stable/c/94d286fa5eedc550d42bcb9c85416af8f77736ff"},{"url":"https://git.kernel.org/stable/c/a3fdd924d88c30b9f488636ce0e4696012cf5511"}],"tags":["cve.org"],"epss":0.00121,"epssPercentile":0.01935,"ingestedAt":"2026-11-06T16:57:43.259Z","slug":"CVE-2026-53274","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS\n\nA logic flaw in __smc_setsockopt() allows a local unprivileged user to\ncause a Denial of Service (DoS) by holding the socket lock indefinitely.\n\nThe function __smc_setsockopt() calls copy_from_sockptr() while holding\nlock_sock(sk). By passing a userfaultfd-monitored memory page (or\nFUSE-backed memory on systems where unprivileged userfaultfd is disabled)\nas the optval, an attacker can halt execution during the copy operation,\nkeeping the lock held.\n\nCombined with asynchronous tear-down operations like shutdown(), this\nexhausts the kernel wq (kworkers) and triggers the hung task watchdog.\n\n[  240.123456] INFO: task kworker/u8:2 blocked for more than 120 seconds.\n[  240.123489] Call Trace:\n[  240.123501]  smc_shutdown+...\n[  240.123512]  lock_sock_nested+...\n\nThis patch moves the user-space copy outside the lock_sock() critical\nsection to prevent the issue.\n\n## Affected\n\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 35a22117839602bb52283de08894c5a7dde92420`\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 5d27d2ffe487df89ce28fda0410eafa05dbe03a0`\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 89f6fbe0033c942cb790ffd53ca93a45eeaf1c91`\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < dcd90f42a33e4220385f27b515183d0c91b2fc4a`\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < 94d286fa5eedc550d42bcb9c85416af8f77736ff`\n- `Linux >= a6a6fe27bab48f0d09a64b051e7bde432fcae081 < a3fdd924d88c30b9f488636ce0e4696012cf5511`\n- `Linux 5.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}