CVE-2022-49068
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
btrfs: release correct delalloc amount in direct IO write path
Running generic/406 causes the following WARNING in btrfs_destroy_inode() which tells there are outstanding extents left.
In btrfs_get_blocks_direct_write(), we reserve a temporary outstanding extents with btrfs_delalloc_reserve_metadata() (or indirectly from btrfs_delalloc_reserve_space(()). We then release the outstanding extents with btrfs_delalloc_release_extents(). However, the "len" can be modified in the COW case, which releases fewer outstanding extents than expected.
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Fix it by calling btrfs_delalloc_release_extents() for the original length.
To reproduce the warning, the filesystem should be 1 GiB. It's triggering a short-write, due to not being able to allocate a large extent and instead allocating a smaller one.
Detalles técnicos trazas, registros y código del informe original
WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs] Modules linked in: btrfs blake2b_generic xor lzo_compress lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram zsmalloc CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs] RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000 RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78 RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8 R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800 R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68 FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> destroy_inode+0x33/0x70 dispose_list+0x43/0x60 evict_inodes+0x161/0x1b0 generic_shutdown_super+0x2d/0x110 kill_anon_super+0xf/0x20 btrfs_kill_super+0xd/0x20 [btrfs] deactivate_locked_super+0x27/0x90 cleanup_mnt+0x12c/0x180 task_work_run+0x54/0x80 exit_to_user_mode_prepare+0x152/0x160 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f854a000fb7
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: 0.26%
- Percentil entre todas las CVEs puntuadas: 16
- 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
JSON original (NVD)
Mostrar
{
"id": "CVE-2022-49068",
"cveTags": [],
"metrics": {
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"source": "nvd@nist.gov",
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"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"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",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
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"published": "2025-02-26T07:00:44.027",
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"source": "nvd@nist.gov",
"description": [
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"descriptions": [
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: release correct delalloc amount in direct IO write path\n\nRunning generic/406 causes the following WARNING in btrfs_destroy_inode()\nwhich tells there are outstanding extents left.\n\nIn btrfs_get_blocks_direct_write(), we reserve a temporary outstanding\nextents with btrfs_delalloc_reserve_metadata() (or indirectly from\nbtrfs_delalloc_reserve_space(()). We then release the outstanding extents\nwith btrfs_delalloc_release_extents(). However, the \"len\" can be modified\nin the COW case, which releases fewer outstanding extents than expected.\n\nFix it by calling btrfs_delalloc_release_extents() for the original length.\n\nTo reproduce the warning, the filesystem should be 1 GiB. It's\ntriggering a short-write, due to not being able to allocate a large\nextent and instead allocating a smaller one.\n\n WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs]\n Modules linked in: btrfs blake2b_generic xor lzo_compress\n lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram\n zsmalloc\n CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014\n RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs]\n RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206\n RAX: 0000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000\n RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78\n RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8\n R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800\n R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68\n FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n <TASK>\n destroy_inode+0x33/0x70\n dispose_list+0x43/0x60\n evict_inodes+0x161/0x1b0\n generic_shutdown_super+0x2d/0x110\n kill_anon_super+0xf/0x20\n btrfs_kill_super+0xd/0x20 [btrfs]\n deactivate_locked_super+0x27/0x90\n cleanup_mnt+0x12c/0x180\n task_work_run+0x54/0x80\n exit_to_user_mode_prepare+0x152/0x160\n syscall_exit_to_user_mode+0x12/0x30\n do_syscall_64+0x42/0x80\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n RIP: 0033:0x7f854a000fb7"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: libera la cantidad correcta de delalloc en la ruta de escritura de E/S directa. La ejecución de generic/406 provoca la siguiente ADVERTENCIA en btrfs_destroy_inode() que indica que quedan extensiones pendientes. En btrfs_get_blocks_direct_write(), reservamos extensiones pendientes temporalmente con btrfs_delalloc_reserve_metadata() (o indirectamente desde btrfs_delalloc_reserve_space()). Luego, liberamos las extensiones pendientes con btrfs_delalloc_release_extents(). Sin embargo, la \"longitud\" se puede modificar en el caso de COW, que libera menos extensiones pendientes de lo esperado. Arréglelo llamando a btrfs_delalloc_release_extents() para la longitud original. Para reproducir la advertencia, el sistema de archivos debe ser de 1 GiB. Está activando una escritura corta, debido a que no se puede asignar una extensión grande y, en su lugar, se asigna una más pequeña. ADVERTENCIA: CPU: 0 PID: 757 en fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs] Módulos vinculados en: btrfs blake2b_generic xor lzo_compress lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram zsmalloc CPU: 0 PID: 757 Comm: umount No contaminado 5.17.0-rc8+ #101 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS d55cb5a 01/04/2014 RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs] RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206 RAX: 000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000 RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78 RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8 R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800 R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68 FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Seguimiento de llamadas: destroy_inode+0x33/0x70 dispose_list+0x43/0x60 evict_inodes+0x161/0x1b0 generic_shutdown_super+0x2d/0x110 kill_anon_super+0xf/0x20 btrfs_kill_super+0xd/0x20 [btrfs] deactivate_locked_super+0x27/0x90 cleanup_mnt+0x12c/0x180 task_work_run+0x54/0x80 exit_to_user_mode_prepare+0x152/0x160 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f854a000fb7"
}
],
"lastModified": "2026-06-17T05:16:59.537",
"configurations": [
{
"nodes": [
{
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