CVE-2024-56686 Affecting kernel-abi-whitelists package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL7-KERNELABIWHITELISTS-8587412
- published31 Dec 2024
- disclosed28 Dec 2024
Introduced: 28 Dec 2024
NewCVE-2024-56686 (opens in a new tab)How to fix?
There is no fixed version for RHEL:7 kernel-abi-whitelists.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-abi-whitelists package and not the kernel-abi-whitelists package as distributed by RHEL.
See How to fix? for RHEL:7 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix race in buffer_head read fault injection
When I enabled ext4 debug for fault injection testing, I encountered the following warning:
EXT4-fs error (device sda): ext4_read_inode_bitmap:201: comm fsstress: Cannot read inode bitmap - block_group = 8, inode_bitmap = 1051 WARNING: CPU: 0 PID: 511 at fs/buffer.c:1181 mark_buffer_dirty+0x1b3/0x1d0
The root cause of the issue lies in the improper implementation of ext4's buffer_head read fault injection. The actual completion of buffer_head read and the buffer_head fault injection are not atomic, which can lead to the uptodate flag being cleared on normally used buffer_heads in race conditions.
[CPU0] [CPU1] [CPU2] ext4_read_inode_bitmap ext4_read_bh() <bh read complete> ext4_read_inode_bitmap if (buffer_uptodate(bh)) return bh jbd2_journal_commit_transaction __jbd2_journal_refile_buffer __jbd2_journal_unfile_buffer __jbd2_journal_temp_unlink_buffer ext4_simulate_fail_bh() clear_buffer_uptodate mark_buffer_dirty <report warning> WARN_ON_ONCE(!buffer_uptodate(bh))
The best approach would be to perform fault injection in the IO completion callback function, rather than after IO completion. However, the IO completion callback function cannot get the fault injection code in sb.
Fix it by passing the result of fault injection into the bh read function, we simulate faults within the bh read function itself. This requires adding an extra parameter to the bh read functions that need fault injection.
References
- https://access.redhat.com/security/cve/CVE-2024-56686
- https://git.kernel.org/stable/c/25a5acf88fed59e060405bbb48098f4a3a2c2adc
- https://git.kernel.org/stable/c/2f3d93e210b9c2866c8b3662adae427d5bf511ec
- https://git.kernel.org/stable/c/61832ee7fa2fbd569d129379e795038abfb0d128
- https://git.kernel.org/stable/c/77035e4d27e15f87ea55929c8bb8fb1970129e2f