CVE-2022-50344
ext4: fix null-ptr-deref in ext4_write_info
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix null-ptr-deref in ext4_write_info 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:ext4_write_info+0x53/0x1b0 [...] Call Trace: dquot_writeback_dquots+0x341/0x9a0 ext4_sync_fs+0x19e/0x800 __sync_filesystem+0x83/0x100 sync_filesystem+0x89/0xf0 generic_shutdown_super+0x79/0x3e0 kill_block_super+0xa1/0x110 deactivate_locked_super+0xac/0x130 deactivate_super+0xb6/0xd0 cleanup_mnt+0x289/0x400 __cleanup_mnt+0x16/0x20 task_work_run+0x11c/0x1c0 exit_to_user_mode_prepare+0x203/0x210 syscall_exit_to_user_mode+0x5b/0x3a0 do_syscall_64+0x59/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ================================================================== Above issue may happen as follows: ------------------------------------- exit_to_user_mode_prepare task_work_run __cleanup_mnt cleanup_mnt deactivate_super deactivate_locked_super kill_block_super generic_shutdown_super shrink_dcache_for_umount dentry = sb->s_root sb->s_root = NULL <--- Here set NULL sync_filesystem __sync_filesystem sb->s_op->sync_fs > ext4_sync_fs dquot_writeback_dquots sb->dq_op->write_info > ext4_write_info ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2) d_inode(sb->s_root) s_root->d_inode <--- Null pointer dereference To solve this problem, we use ext4_journal_start_sb directly to avoid s_root being used.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 94% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < dc451578446afd03c0c21913993c08898a691435
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < f4b5ff0b794aa94afac7269c494550ca2f66511b
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < 947264e00c46de19a016fd81218118c708fed2f3
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < 3638aa1c7d87c0ca0aef23cf58cae2c48e7daca4
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < f34ab95162763cd7352f46df169296eec28b688d
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < 533c60a0b97cee5daab376933f486207e6680fb7
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < 4a657319cfabd6199fd0b7b65bbebf6ded7a11c1
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < bb420e8afc854d2a1caaa23a0c129839acfb7888
- affected a1177825719ccef3f76ef39bbfd5ebb6087d53c7 – < f9c1f248607d5546075d3f731e7607d5571f2b60
- affected 3.6
- unaffected < 3.6
- unaffected 4.9.331 – ≤ 4.9.*
- unaffected 4.14.296 – ≤ 4.14.*
- unaffected 4.19.262 – ≤ 4.19.*
- unaffected 5.4.220 – ≤ 5.4.*
- unaffected 5.10.150 – ≤ 5.10.*
- unaffected 5.15.75 – ≤ 5.15.*
- unaffected 5.19.17 – ≤ 5.19.*
- unaffected 6.0.3 – ≤ 6.0.*
- unaffected 6.1 – ≤ *
References (9)
- https://git.kernel.org/stable/c/dc451578446afd03c0c21913993c08898a691435 (opens in a new tab)
- https://git.kernel.org/stable/c/f4b5ff0b794aa94afac7269c494550ca2f66511b (opens in a new tab)
- https://git.kernel.org/stable/c/947264e00c46de19a016fd81218118c708fed2f3 (opens in a new tab)
- https://git.kernel.org/stable/c/3638aa1c7d87c0ca0aef23cf58cae2c48e7daca4 (opens in a new tab)
- https://git.kernel.org/stable/c/f34ab95162763cd7352f46df169296eec28b688d (opens in a new tab)
- https://git.kernel.org/stable/c/533c60a0b97cee5daab376933f486207e6680fb7 (opens in a new tab)
- https://git.kernel.org/stable/c/4a657319cfabd6199fd0b7b65bbebf6ded7a11c1 (opens in a new tab)
- https://git.kernel.org/stable/c/bb420e8afc854d2a1caaa23a0c129839acfb7888 (opens in a new tab)
- https://git.kernel.org/stable/c/f9c1f248607d5546075d3f731e7607d5571f2b60 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2022-50344)Record last updated .