CVE-2026-64139

CVE CVE-2026-64139EUVD EUVD-2026-45824Published 2026-07-19T15:40:32.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16 DACL size overflow") added check_add_overflow() guards that break out of the ACE-building loops in set_posix_acl_entries_dacl() when the accumulated DACL size would wrap past 65535. However, each iteration allocates a struct smb_sid via kmalloc_obj() at the top of the loop and relies on the kfree(sid) call at the end of the loop body (the 'pass_same_sid' label in the first loop, and the explicit kfree at the tail of the second loop) to release it. The newly introduced 'break' statements bypass those kfree() calls, leaking the sid buffer every time an overflow is detected. A malicious or malformed file with enough POSIX ACL entries to trip the overflow check will leak one or more struct smb_sid allocations on every request that touches the file's DACL, providing a trivial kernel memory exhaustion vector. Free sid before breaking out of the loops to plug the leak.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7 <eced48cb08f07393a5ea770fdd1026452883c3ad; 6.6.136 <6.6.142; 8d5729350b236896f51379588d9a690b7fafb8db <9d378e17c864da08c3a4df41dae92cfa6468b00a; 6.12.84 <6.12.92; 7.0.2 <7.0.11; 6.18.25 <6.18.34; 5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43 <0e198f09cb2a554c04de0fea4e790f1250a943ca; 41e53a773db6342ac9a689ee5ba635c31744c9f0; e1955a94b6f17f4b058afa955a6f187eb3ed7615 <519fb0a42ce5d7e46935577309fb282a5f2c6ea3; 299f962c0b02d048fb45d248b4da493d03f3175d <af92ee994cc7f7e83a41c2025f32257a2f82a7ef; 6.1.175 <6.2

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.