GHSA-F5WJ-8Q5W-FQWR
Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33In 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.
{
"affected": [],
"aliases": [
"CVE-2026-46061"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-27T14:17:25Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\njbd2: fix deadlock in jbd2_journal_cancel_revoke()\n\nCommit f76d4c28a46a (\"fs/jbd2: use sleeping version of\n__find_get_block()\") changed jbd2_journal_cancel_revoke() to use\n__find_get_block_nonatomic() which holds the folio lock instead of\ni_private_lock. This breaks the lock ordering (folio -\u003e buffer) and\ncauses an ABBA deadlock when the filesystem blocksize \u003c pagesize:\n\n T1 T2\next4_mkdir()\n ext4_init_new_dir()\n ext4_append()\n ext4_getblk()\n lock_buffer() \u003c- A\n sync_blockdev()\n blkdev_writepages()\n writeback_iter()\n writeback_get_folio()\n folio_lock() \u003c- B\n ext4_journal_get_create_access()\n jbd2_journal_cancel_revoke()\n __find_get_block_nonatomic()\n folio_lock() \u003c- B\n block_write_full_folio()\n lock_buffer() \u003c- A\n\nThis can occasionally cause generic/013 to hang.\n\nFix by only calling __find_get_block_nonatomic() when the passed\nbuffer_head doesn\u0027t belong to the bdev, which is the only case that we\nneed to look up its bdev alias. Otherwise, the lookup is redundant since\nthe found buffer_head is equal to the one we passed in.",
"id": "GHSA-f5wj-8q5w-fqwr",
"modified": "2026-05-27T15:33:22Z",
"published": "2026-05-27T15:33:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46061"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2b2fee890250ab647a601124471a334bb01a0790"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/981fcc5674e67158d24d23e841523eccba19d0e7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bbd943d6a2d566428324b516a37f98328dfb802d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dff07cc98fdf6af57a7c054dc09b2050a9d5c287"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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