ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() (Linux Linux)

CVE-2024-39276
MEDIUM 5.5

En bref

Source
NVD
EPSS
EPSS 0.23 % · centile 14 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
Linux
Statut NVD
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NCISA-ADP
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

Références européennes

Avis du CERT-FR

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
Linux · Linuxaffected b878c8a7f08f0c225b6a46ba1ac867e9c5d17807 < 9ad75e78747b5a50dc5a52f0f8e92e920a653f16 ; affected fb265c9cb49e2074ddcdd4de99728aefdd3b3592 < 896a7e7d0d555ad8b2b46af0c2fa7de7467f9483 ; affected fb265c9cb49e2074ddcdd4de99728aefdd3b3592 < 76dc776153a47372719d664e0fc50d6355791abb ; affected fb265c9cb49e2074ddcdd4de99728aefdd3b3592 < 681ff9a09accd8a4379f8bd30b7a1641ee19bb3e ; affected fb265c9cb49e2074ddcdd4de99728aefdd3b3592 < e941b712e758f615d311946bf98216e79145ccd9 ; affected fb265c9cb49e2074ddcdd4de99728aefdd3b3592 < a95df6f04f2c37291adf26a74205cde0314d4577
Linux · Linuxaffected 5.0 ; unaffected 0 < 5.0 ; unaffected 4.19.316 ≤ 4.19.* ; unaffected 5.4.278 ≤ 5.4.* ; unaffected 5.10.219 ≤ 5.10.* ; unaffected 5.15.161 ≤ 5.15.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD