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CVE-2024-26685

nilfs2: fix potential bug in end_buffer_async_write PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before c4a09fdac625e64abe478dcf88bfa20406616928; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before d31c8721e816eff5ca6573cc487754f357c093cd; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before f3e4963566f58726d3265a727116a42b591f6596; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before 8fa90634ec3e9cc50f42dd605eec60f2d146ced8; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before 6589f0f72f8edd1fa11adce4eedbd3615f2e78ab; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before 2c3bdba00283a6c7a5b19481a59a730f46063803; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before 626daab3811b772086aef1bf8eed3ffe6f523eff; affected 7f42ec3941560f0902fe3671e36f2c20ffd3af0a before 5bc09b397cbf1221f8a8aacb1152650c9195b02b; affected ccebcc74c81d8399c7b204aea47c1f33b09c2b17; affected 831c87640d23ccb253a02e4901bd9a325b5e8c2d; affected d8974c7fe717ee8fb0706e35cc92e0bcdf660ec5; affected 8f67918af09fc0ffd426a9b6f87697976d3fbc7b; affected 3.2.52 before 3.3; affected 3.4.83 before 3.5; affected 3.10.16 before 3.11; affected 3.11.5 before 3.12
Linux / Linuxaffected 3.12; unaffected 0 before 3.12; unaffected 4.19.307 through 4.19.*; unaffected 5.4.269 through 5.4.*; unaffected 5.10.210 through 5.10.*; unaffected 5.15.149 through 5.15.*; unaffected 6.1.79 through 6.1.*; unaffected 6.6.18 through 6.6.*; unaffected 6.7.6 through 6.7.*; unaffected 6.8 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

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No references supplied.

CVE

No English description supplied.