CVE-2022-50344

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2022-50344
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-50344.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2022-50344
Downstream
Related
Published
2025-09-16T16:11:23.345Z
Modified
2026-03-20T12:22:34.394244Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
ext4: fix null-ptr-deref in ext4_write_info
Details

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

ext4: fix null-ptr-deref in ext4writeinfo

I caught a null-ptr-deref bug as follows:

KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339 RIP: 0010:ext4writeinfo+0x53/0x1b0 [...] Call Trace: dquotwritebackdquots+0x341/0x9a0 ext4syncfs+0x19e/0x800 __syncfilesystem+0x83/0x100 syncfilesystem+0x89/0xf0 genericshutdownsuper+0x79/0x3e0 killblocksuper+0xa1/0x110 deactivatelockedsuper+0xac/0x130 deactivatesuper+0xb6/0xd0 cleanupmnt+0x289/0x400 _cleanupmnt+0x16/0x20 taskworkrun+0x11c/0x1c0 exittousermodeprepare+0x203/0x210 syscallexittousermode+0x5b/0x3a0 dosyscall64+0x59/0x70 entrySYSCALL64afterhwframe+0x44/0xa9 ==================================================================

Above issue may happen as follows:

exittousermodeprepare taskworkrun __cleanupmnt cleanupmnt deactivate_super deactivatelockedsuper killblocksuper genericshutdownsuper shrinkdcacheforumount dentry = sb->sroot sb->sroot = NULL <--- Here set NULL syncfilesystem _syncfilesystem sb->sop->syncfs > ext4syncfs dquotwritebackdquots sb->dqop->writeinfo > ext4writeinfo ext4journalstart(dinode(sb->sroot), EXT4HTQUOTA, 2) dinode(sb->sroot) sroot->dinode <--- Null pointer dereference

To solve this problem, we use ext4journalstartsb directly to avoid sroot being used.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/50xxx/CVE-2022-50344.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
a1177825719ccef3f76ef39bbfd5ebb6087d53c7
Fixed
dc451578446afd03c0c21913993c08898a691435
Fixed
f4b5ff0b794aa94afac7269c494550ca2f66511b
Fixed
947264e00c46de19a016fd81218118c708fed2f3
Fixed
3638aa1c7d87c0ca0aef23cf58cae2c48e7daca4
Fixed
f34ab95162763cd7352f46df169296eec28b688d
Fixed
533c60a0b97cee5daab376933f486207e6680fb7
Fixed
4a657319cfabd6199fd0b7b65bbebf6ded7a11c1
Fixed
bb420e8afc854d2a1caaa23a0c129839acfb7888
Fixed
f9c1f248607d5546075d3f731e7607d5571f2b60

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-50344.json"