CVE-2026-46061
jbd2: fix deadlock in jbd2_journal_cancel_revoke()
Description
In the Linux kernel, the following vulnerability has been resolved: jbd2: fix deadlock in jbd2_journal_cancel_revoke() Commit f76d4c28a46a ("fs/jbd2: use sleeping version of __find_get_block()") changed jbd2_journal_cancel_revoke() to use __find_get_block_nonatomic() which holds the folio lock instead of i_private_lock. This breaks the lock ordering (folio -> buffer) and causes an ABBA deadlock when the filesystem blocksize < pagesize: T1 T2 ext4_mkdir() ext4_init_new_dir() ext4_append() ext4_getblk() lock_buffer() <- A sync_blockdev() blkdev_writepages() writeback_iter() writeback_get_folio() folio_lock() <- B ext4_journal_get_create_access() jbd2_journal_cancel_revoke() __find_get_block_nonatomic() folio_lock() <- B block_write_full_folio() lock_buffer() <- A This can occasionally cause generic/013 to hang. Fix by only calling __find_get_block_nonatomic() when the passed buffer_head doesn't belong to the bdev, which is the only case that we need to look up its bdev alias. Otherwise, the lookup is redundant since the found buffer_head is equal to the one we passed in.
INFO
Published Date :
May 27, 2026, 2:17 p.m.
Last Modified :
May 27, 2026, 2:48 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the fix for the jbd2 deadlock in the Linux kernel.
- Ensure correct lock ordering is maintained in jbd2 journal operations.
- Only call specific block lookup when necessary.
- Update kernel to version with the fix.
References to Advisories, Solutions, and Tools
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CVE-2026-46061.
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-46061
weaknesses.
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 27, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: jbd2: fix deadlock in jbd2_journal_cancel_revoke() Commit f76d4c28a46a ("fs/jbd2: use sleeping version of __find_get_block()") changed jbd2_journal_cancel_revoke() to use __find_get_block_nonatomic() which holds the folio lock instead of i_private_lock. This breaks the lock ordering (folio -> buffer) and causes an ABBA deadlock when the filesystem blocksize < pagesize: T1 T2 ext4_mkdir() ext4_init_new_dir() ext4_append() ext4_getblk() lock_buffer() <- A sync_blockdev() blkdev_writepages() writeback_iter() writeback_get_folio() folio_lock() <- B ext4_journal_get_create_access() jbd2_journal_cancel_revoke() __find_get_block_nonatomic() folio_lock() <- B block_write_full_folio() lock_buffer() <- A This can occasionally cause generic/013 to hang. Fix by only calling __find_get_block_nonatomic() when the passed buffer_head doesn't belong to the bdev, which is the only case that we need to look up its bdev alias. Otherwise, the lookup is redundant since the found buffer_head is equal to the one we passed in. Added Reference https://git.kernel.org/stable/c/2b2fee890250ab647a601124471a334bb01a0790 Added Reference https://git.kernel.org/stable/c/981fcc5674e67158d24d23e841523eccba19d0e7 Added Reference https://git.kernel.org/stable/c/bbd943d6a2d566428324b516a37f98328dfb802d Added Reference https://git.kernel.org/stable/c/dff07cc98fdf6af57a7c054dc09b2050a9d5c287