# CVE-2026-53274: net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS CVE-2026-53274 is fixed in 16 products on 1 platform, first by DEBIAN-CVE-2026-53274, released June 25, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-53274 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0012 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 25, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53274 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.36.1.160000.2.17 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.73.2.150700.17.41.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.36.1.160000.2.17 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_18 sles 15.7 | 1-150700.1.5.1 | [SUSE-SU-2026:3130-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3130-1.md) | Jul 20, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_19 sles 15.7 | 1-150700.15.3.4 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.73.1 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.73.2 | [SUSE-SU-2026:3166-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3166-1.md) | Jul 21, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.176-1 | [DEBIAN-CVE-2026-53274](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53274.md) | Jun 25, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-53274](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53274.md) | Jun 25, 2026 | | Linux | linux Debian 14 | 7.0.13-1 | [DEBIAN-CVE-2026-53274](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53274.md) | Jun 25, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.