{"id":"CVE-2021-47510","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix re-dirty process of tree-log nodes\n\nThere is a report of a transaction abort of -EAGAIN with the following\nscript.\n\n  #!/bin/sh\n\n  for d in sda sdb; do\n          mkfs.btrfs -d single -m single -f /dev/\\${d}\n  done\n\n  mount /dev/sda /mnt/test\n  mount /dev/sdb /mnt/scratch\n\n  for dir in test scratch; do\n          echo 3 \u003e/proc/sys/vm/drop_caches\n          fio --directory=/mnt/\\${dir} --name=fio.\\${dir} --rw=read --size=50G --bs=64m \\\n                  --numjobs=$(nproc) --time_based --ramp_time=5 --runtime=480 \\\n                  --group_reporting |& tee /dev/shm/fio.\\${dir}\n          echo 3 \u003e/proc/sys/vm/drop_caches\n  done\n\n  for d in sda sdb; do\n          umount /dev/\\${d}\n  done\n\nThe stack trace is shown in below.\n\n  [3310.967991] BTRFS: error (device sda) in btrfs_commit_transaction:2341: errno=-11 unknown (Error while writing out transaction)\n  [3310.968060] BTRFS info (device sda): forced readonly\n  [3310.968064] BTRFS warning (device sda): Skipping commit of aborted transaction.\n  [3310.968065] ------------[ cut here ]------------\n  [3310.968066] BTRFS: Transaction aborted (error -11)\n  [3310.968074] WARNING: CPU: 14 PID: 1684 at fs/btrfs/transaction.c:1946 btrfs_commit_transaction.cold+0x209/0x2c8\n  [3310.968131] CPU: 14 PID: 1684 Comm: fio Not tainted 5.14.10-300.fc35.x86_64 #1\n  [3310.968135] Hardware name: DIAWAY Tartu/Tartu, BIOS V2.01.B10 04/08/2021\n  [3310.968137] RIP: 0010:btrfs_commit_transaction.cold+0x209/0x2c8\n  [3310.968144] RSP: 0018:ffffb284ce393e10 EFLAGS: 00010282\n  [3310.968147] RAX: 0000000000000026 RBX: ffff973f147b0f60 RCX: 0000000000000027\n  [3310.968149] RDX: ffff974ecf098a08 RSI: 0000000000000001 RDI: ffff974ecf098a00\n  [3310.968150] RBP: ffff973f147b0f08 R08: 0000000000000000 R09: ffffb284ce393c48\n  [3310.968151] R10: ffffb284ce393c40 R11: ffffffff84f47468 R12: ffff973f101bfc00\n  [3310.968153] R13: ffff971f20cf2000 R14: 00000000fffffff5 R15: ffff973f147b0e58\n  [3310.968154] FS:  00007efe65468740(0000) GS:ffff974ecf080000(0000) knlGS:0000000000000000\n  [3310.968157] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  [3310.968158] CR2: 000055691bcbe260 CR3: 000000105cfa4001 CR4: 0000000000770ee0\n  [3310.968160] PKRU: 55555554\n  [3310.968161] Call Trace:\n  [3310.968167]  ? dput+0xd4/0x300\n  [3310.968174]  btrfs_sync_file+0x3f1/0x490\n  [3310.968180]  __x64_sys_fsync+0x33/0x60\n  [3310.968185]  do_syscall_64+0x3b/0x90\n  [3310.968190]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n  [3310.968194] RIP: 0033:0x7efe6557329b\n  [3310.968200] RSP: 002b:00007ffe0236ebc0 EFLAGS: 00000293 ORIG_RAX: 000000000000004a\n  [3310.968203] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efe6557329b\n  [3310.968204] RDX: 0000000000000000 RSI: 00007efe58d77010 RDI: 0000000000000006\n  [3310.968205] RBP: 0000000004000000 R08: 0000000000000000 R09: 00007efe58d77010\n  [3310.968207] R10: 0000000016cacc0c R11: 0000000000000293 R12: 00007efe5ce95980\n  [3310.968208] R13: 0000000000000000 R14: 00007efe6447c790 R15: 0000000c80000000\n  [3310.968212] ---[ end trace 1a346f4d3c0d96ba ]---\n  [3310.968214] BTRFS: error (device sda) in cleanup_transaction:1946: errno=-11 unknown\n\nThe abort occurs because of a write hole while writing out freeing tree\nnodes of a tree-log tree. For zoned btrfs, we re-dirty a freed tree\nnode to ensure btrfs can write the region and does not leave a hole on\nwrite on a zoned device. The current code fails to re-dirty a node\nwhen the tree-log tree's depth is greater or equal to 2. That leads to\na transaction abort with -EAGAIN.\n\nFix the issue by properly re-dirtying a node on walking up the tree.","modified":"2026-03-13T05:20:47.016022Z","published":"2024-05-24T15:15:12Z","related":["SUSE-SU-2024:2008-1","SUSE-SU-2024:2011-1","SUSE-SU-2024:2019-1","SUSE-SU-2024:2189-1","SUSE-SU-2024:2190-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/477675049ca803aa95ff77468ffbddd966b415b0"},{"type":"FIX","url":"https://git.kernel.org/stable/c/84c25448929942edacba905cecc0474e91114e7a"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"5.12"},{"fixed":"5.15.8"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc3"}]},{"events":[{"introduced":"0"},{"last_affected":"5.16-rc4"}]}],"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-47510.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}