| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-26685: nilfs2: fix potential bug in end_buffer_async_write |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| nilfs2: fix potential bug in end_buffer_async_write |
| |
| According to a syzbot report, end_buffer_async_write(), which handles the |
| completion of block device writes, may detect abnormal condition of the |
| buffer async_write flag and cause a BUG_ON failure when using nilfs2. |
| |
| Nilfs2 itself does not use end_buffer_async_write(). But, the async_write |
| flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue |
| with race condition of competition between segments for dirty blocks") as |
| a means of resolving double list insertion of dirty blocks in |
| nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the |
| resulting crash. |
| |
| This modification is safe as long as it is used for file data and b-tree |
| node blocks where the page caches are independent. However, it was |
| irrelevant and redundant to also introduce async_write for segment summary |
| and super root blocks that share buffers with the backing device. This |
| led to the possibility that the BUG_ON check in end_buffer_async_write |
| would fail as described above, if independent writebacks of the backing |
| device occurred in parallel. |
| |
| The use of async_write for segment summary buffers has already been |
| removed in a previous change. |
| |
| Fix this issue by removing the manipulation of the async_write flag for |
| the remaining super root block buffer. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26685 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 4.19.307 with commit c4a09fdac625e64abe478dcf88bfa20406616928 |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 5.4.269 with commit d31c8721e816eff5ca6573cc487754f357c093cd |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 5.10.210 with commit f3e4963566f58726d3265a727116a42b591f6596 |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 5.15.149 with commit 8fa90634ec3e9cc50f42dd605eec60f2d146ced8 |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 6.1.79 with commit 6589f0f72f8edd1fa11adce4eedbd3615f2e78ab |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 6.6.18 with commit 2c3bdba00283a6c7a5b19481a59a730f46063803 |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 6.7.6 with commit 626daab3811b772086aef1bf8eed3ffe6f523eff |
| Issue introduced in 3.12 with commit 7f42ec3941560f0902fe3671e36f2c20ffd3af0a and fixed in 6.8 with commit 5bc09b397cbf1221f8a8aacb1152650c9195b02b |
| Issue introduced in 3.2.52 with commit ccebcc74c81d8399c7b204aea47c1f33b09c2b17 |
| Issue introduced in 3.4.83 with commit 831c87640d23ccb253a02e4901bd9a325b5e8c2d |
| Issue introduced in 3.10.16 with commit d8974c7fe717ee8fb0706e35cc92e0bcdf660ec5 |
| Issue introduced in 3.11.5 with commit 8f67918af09fc0ffd426a9b6f87697976d3fbc7b |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-26685 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/nilfs2/segment.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/c4a09fdac625e64abe478dcf88bfa20406616928 |
| https://git.kernel.org/stable/c/d31c8721e816eff5ca6573cc487754f357c093cd |
| https://git.kernel.org/stable/c/f3e4963566f58726d3265a727116a42b591f6596 |
| https://git.kernel.org/stable/c/8fa90634ec3e9cc50f42dd605eec60f2d146ced8 |
| https://git.kernel.org/stable/c/6589f0f72f8edd1fa11adce4eedbd3615f2e78ab |
| https://git.kernel.org/stable/c/2c3bdba00283a6c7a5b19481a59a730f46063803 |
| https://git.kernel.org/stable/c/626daab3811b772086aef1bf8eed3ffe6f523eff |
| https://git.kernel.org/stable/c/5bc09b397cbf1221f8a8aacb1152650c9195b02b |
