CVE-2024-39276

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Source
https://cve.org/CVERecord?id=CVE-2024-39276
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-39276.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2024-39276
Downstream
Related
Published
2024-06-25T14:22:38.886Z
Modified
2026-03-13T07:56:59.278607Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
Summary
ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()
Details

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix mbcacheentry's erefcnt leak in ext4xattrblockcache_find()

Syzbot reports a warning as follows:

============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mbcachedestroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mbcachedestroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4putsuper+0x6d4/0xcd0 fs/ext4/super.c:1375 genericshutdownsuper+0x136/0x2d0 fs/super.c:641 killblocksuper+0x44/0x90 fs/super.c:1675 ext4killsb+0x68/0xa0 fs/ext4/super.c:7327

[...]

This is because when finding an entry in ext4xattrblockcachefind(), if ext4sbbread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the _entryfind(), won't be put away, and eventually trigger the above issue in mbcachedestroy() due to reference count leakage.

So call mbcacheentry_put() on the -ENOMEM error branch as a quick fix.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/39xxx/CVE-2024-39276.json",
    "cna_assigner": "Linux"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
b878c8a7f08f0c225b6a46ba1ac867e9c5d17807
Fixed
9ad75e78747b5a50dc5a52f0f8e92e920a653f16
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
fb265c9cb49e2074ddcdd4de99728aefdd3b3592
Fixed
896a7e7d0d555ad8b2b46af0c2fa7de7467f9483
Fixed
76dc776153a47372719d664e0fc50d6355791abb
Fixed
681ff9a09accd8a4379f8bd30b7a1641ee19bb3e
Fixed
e941b712e758f615d311946bf98216e79145ccd9
Fixed
a95df6f04f2c37291adf26a74205cde0314d4577
Fixed
b37c0edef4e66fb21a2fbc211471195a383e5ab8
Fixed
0c0b4a49d3e7f49690a6827a41faeffad5df7e21
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
9da1f6d06b7a6d068e68fcfd7cbbf6b586d888e1
Last affected
81313ed2c705d958744882a269bf4a5e3ddec95e

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-39276.json"