CVE-2026-53274: net/smc: fix sleep-inside-lock in __smc_setsockopt() causing local DoS
Vulnerability summary
CVE-2026-53274 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.9% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 29 · Related 29Timeline
- 25-06-2026PublishedVulnerability first disclosed.
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.
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.12%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.12% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu141 products
- linux< 6.8.0-146.146 | All versions (No fix recorded) | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1066.69 | All versions (No fix recorded) | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Chainguard6 products
- linux-azure-6.18< 6.18.38-r0
- linux-gcp-6.18< 6.18.38-r0
- linux-gcp-6.18-bootc-boot-installed< 6.18.38-r0
- linux-qemu-6.18< 6.18.38-r0
- linux-qemu-6.18-bootc-boot-installed< 6.18.38-r0
Linux2 products
- linux≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < 35a22117839602bb52283de08894c5a7dde92420 | ≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < 5d27d2ffe487df89ce28fda0410eafa05dbe03a0 | ≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < 89f6fbe0033c942cb790ffd53ca93a45eeaf1c91 | ≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < dcd90f42a33e4220385f27b515183d0c91b2fc4a | ≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < 94d286fa5eedc550d42bcb9c85416af8f77736ff | ≥ a6a6fe27bab48f0d09a64b051e7bde432fcae081, < a3fdd924d88c30b9f488636ce0e4696012cf5511 | 5.18
- linux_kernel≥ 5.18, < 6.1.176 | ≥ 6.2, < 6.6.143 | ≥ 6.7, < 6.12.94 | ≥ 6.13, < 6.18.36 | ≥ 6.19, < 7.0.13 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.13-1
4 vendors · 150 products
