CVE-2024-39276

CVE Details

Release Date:	2024-06-25
Impact:	Low	What is this?

Description

In the Linux kernel, the following vulnerability has been resolved:\next4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()\nSyzbot reports a warning as follows:\n============================================\nWARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290\nModules linked in:\nCPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7\nRIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419\nCall Trace:\n\next4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375\ngeneric_shutdown_super+0x136/0x2d0 fs/super.c:641\nkill_block_super+0x44/0x90 fs/super.c:1675\next4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327\n[...]\n============================================\nThis is because when finding an entry in ext4_xattr_block_cache_find(), if\next4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown\nin the __entry_find(), won't be put away, and eventually trigger the above\nissue in mb_cache_destroy() due to reference count leakage.\nSo call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

See more information about CVE-2024-39276 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	5.5
Vector String:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Version:	3.1
Attack Vector:	Local
Attack Complexity:	Low
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	None
Availability Impact:	None

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (kernel-uek)	ELSA-2024-12581	2024-08-12
Oracle Linux version 7 (kernel-uek)	ELSA-2024-12611	2024-09-11
Oracle Linux version 7 (kernel-uek-container)	ELSA-2024-12585	2024-08-12
Oracle Linux version 8 (kernel)	ELSA-2024-5101	2024-08-08
Oracle Linux version 8 (kernel-uek)	ELSA-2024-12581	2024-08-12
Oracle Linux version 8 (kernel-uek-container)	ELSA-2024-12584	2024-08-12
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14