CVE-2026-45934
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix EEXIST abort due to non-consecutive gaps in chunk allocation
I have been observing a number of systems aborting at insert_dev_extents() in btrfs_create_pending_block_groups(). The following is a sample stack trace of such an abort coming from forced chunk allocation (typically behind CONFIG_BTRFS_EXPERIMENTAL) but this can theoretically happen to any DUP chunk allocation.
Inspecting these aborts with drgn, I observed a pattern of overlapping chunk_maps. Note how stripe 1 of the first chunk overlaps in physical address with stripe 0 of the second chunk.
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Physical Start Physical End Length Logical Type Stripe ---------------------------------------------------------------------------------------------------- 0x0000000102500000 0x0000000142500000 1.0G 0x0000000641d00000 META|DUP 0/2 0x0000000142500000 0x0000000182500000 1.0G 0x0000000641d00000 META|DUP 1/2 0x0000000142500000 0x0000000182500000 1.0G 0x0000000601d00000 META|DUP 0/2 0x0000000182500000 0x00000001c2500000 1.0G 0x0000000601d00000 META|DUP 1/2
Now how could this possibly happen? All chunk allocation is ---truncated---
Detalles técnicos trazas, registros y código del informe original
[81.801] ------------[ cut here ]------------ [81.801] BTRFS: Transaction aborted (error -17) [81.801] WARNING: fs/btrfs/block-group.c:2876 at btrfs_create_pending_block_groups+0x721/0x770 [btrfs], CPU#1: bash/319 [81.802] Modules linked in: virtio_net btrfs xor zstd_compress raid6_pq null_blk [81.803] CPU: 1 UID: 0 PID: 319 Comm: bash Kdump: loaded Not tainted 6.19.0-rc6+ #319 NONE [81.803] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 [81.804] RIP: 0010:btrfs_create_pending_block_groups+0x723/0x770 [btrfs] [81.806] RSP: 0018:ffffa36241a6bce8 EFLAGS: 00010282 [81.806] RAX: 000000000000000d RBX: ffff8e699921e400 RCX: 0000000000000000 [81.807] RDX: 0000000002040001 RSI: 00000000ffffffef RDI: ffffffffc0608bf0 [81.807] RBP: 00000000ffffffef R08: ffff8e69830f6000 R09: 0000000000000007 [81.808] R10: ffff8e699921e5e8 R11: 0000000000000000 R12: ffff8e6999228000 [81.808] R13: ffff8e6984d82000 R14: ffff8e69966a69c0 R15: ffff8e69aa47b000 [81.809] FS: 00007fec6bdd9740(0000) GS:ffff8e6b1b379000(0000) knlGS:0000000000000000 [81.809] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [81.810] CR2: 00005604833670f0 CR3: 0000000116679000 CR4: 00000000000006f0 [81.810] Call Trace: [81.810] <TASK> [81.810] __btrfs_end_transaction+0x3e/0x2b0 [btrfs] [81.811] btrfs_force_chunk_alloc_store+0xcd/0x140 [btrfs] [81.811] kernfs_fop_write_iter+0x15f/0x240 [81.812] vfs_write+0x264/0x500 [81.812] ksys_write+0x6c/0xe0 [81.812] do_syscall_64+0x66/0x770 [81.812] entry_SYSCALL_64_after_hwframe+0x76/0x7e [81.813] RIP: 0033:0x7fec6be66197 [81.814] RSP: 002b:00007fffb159dd30 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [81.815] RAX: ffffffffffffffda RBX: 00007fec6bdd9740 RCX: 00007fec6be66197 [81.815] RDX: 0000000000000002 RSI: 0000560483374f80 RDI: 0000000000000001 [81.816] RBP: 0000560483374f80 R08: 0000000000000000 R09: 0000000000000000 [81.816] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 [81.817] R13: 00007fec6bfb85c0 R14: 00007fec6bfb5ee0 R15: 00005604833729c0 [81.817] </TASK> [81.817] irq event stamp: 20039 [81.818] hardirqs last enabled at (20047): [<ffffffff99a68302>] __up_console_sem+0x52/0x60 [81.818] hardirqs last disabled at (20056): [<ffffffff99a682e7>] __up_console_sem+0x37/0x60 [81.819] softirqs last enabled at (19470): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0 [81.819] softirqs last disabled at (19463): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0 [81.820] ---[ end trace 0000000000000000 ]--- [81.820] BTRFS: error (device dm-7 state A) in btrfs_create_pending_block_groups:2876: errno=-17 Object already exists
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
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-45934",
"cveTags": [],
"metrics": {
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"type": "Primary",
"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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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix EEXIST abort due to non-consecutive gaps in chunk allocation\n\nI have been observing a number of systems aborting at\ninsert_dev_extents() in btrfs_create_pending_block_groups(). The\nfollowing is a sample stack trace of such an abort coming from forced\nchunk allocation (typically behind CONFIG_BTRFS_EXPERIMENTAL) but this\ncan theoretically happen to any DUP chunk allocation.\n\n [81.801] ------------[ cut here ]------------\n [81.801] BTRFS: Transaction aborted (error -17)\n [81.801] WARNING: fs/btrfs/block-group.c:2876 at btrfs_create_pending_block_groups+0x721/0x770 [btrfs], CPU#1: bash/319\n [81.802] Modules linked in: virtio_net btrfs xor zstd_compress raid6_pq null_blk\n [81.803] CPU: 1 UID: 0 PID: 319 Comm: bash Kdump: loaded Not tainted 6.19.0-rc6+ #319 NONE\n [81.803] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014\n [81.804] RIP: 0010:btrfs_create_pending_block_groups+0x723/0x770 [btrfs]\n [81.806] RSP: 0018:ffffa36241a6bce8 EFLAGS: 00010282\n [81.806] RAX: 000000000000000d RBX: ffff8e699921e400 RCX: 0000000000000000\n [81.807] RDX: 0000000002040001 RSI: 00000000ffffffef RDI: ffffffffc0608bf0\n [81.807] RBP: 00000000ffffffef R08: ffff8e69830f6000 R09: 0000000000000007\n [81.808] R10: ffff8e699921e5e8 R11: 0000000000000000 R12: ffff8e6999228000\n [81.808] R13: ffff8e6984d82000 R14: ffff8e69966a69c0 R15: ffff8e69aa47b000\n [81.809] FS: 00007fec6bdd9740(0000) GS:ffff8e6b1b379000(0000) knlGS:0000000000000000\n [81.809] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n [81.810] CR2: 00005604833670f0 CR3: 0000000116679000 CR4: 00000000000006f0\n [81.810] Call Trace:\n [81.810] <TASK>\n [81.810] __btrfs_end_transaction+0x3e/0x2b0 [btrfs]\n [81.811] btrfs_force_chunk_alloc_store+0xcd/0x140 [btrfs]\n [81.811] kernfs_fop_write_iter+0x15f/0x240\n [81.812] vfs_write+0x264/0x500\n [81.812] ksys_write+0x6c/0xe0\n [81.812] do_syscall_64+0x66/0x770\n [81.812] entry_SYSCALL_64_after_hwframe+0x76/0x7e\n [81.813] RIP: 0033:0x7fec6be66197\n [81.814] RSP: 002b:00007fffb159dd30 EFLAGS: 00000202 ORIG_RAX: 0000000000000001\n [81.815] RAX: ffffffffffffffda RBX: 00007fec6bdd9740 RCX: 00007fec6be66197\n [81.815] RDX: 0000000000000002 RSI: 0000560483374f80 RDI: 0000000000000001\n [81.816] RBP: 0000560483374f80 R08: 0000000000000000 R09: 0000000000000000\n [81.816] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002\n [81.817] R13: 00007fec6bfb85c0 R14: 00007fec6bfb5ee0 R15: 00005604833729c0\n [81.817] </TASK>\n [81.817] irq event stamp: 20039\n [81.818] hardirqs last enabled at (20047): [<ffffffff99a68302>] __up_console_sem+0x52/0x60\n [81.818] hardirqs last disabled at (20056): [<ffffffff99a682e7>] __up_console_sem+0x37/0x60\n [81.819] softirqs last enabled at (19470): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0\n [81.819] softirqs last disabled at (19463): [<ffffffff999d2b46>] __irq_exit_rcu+0x96/0xc0\n [81.820] ---[ end trace 0000000000000000 ]---\n [81.820] BTRFS: error (device dm-7 state A) in btrfs_create_pending_block_groups:2876: errno=-17 Object already exists\n\nInspecting these aborts with drgn, I observed a pattern of overlapping\nchunk_maps. Note how stripe 1 of the first chunk overlaps in physical\naddress with stripe 0 of the second chunk.\n\nPhysical Start Physical End Length Logical Type Stripe\n----------------------------------------------------------------------------------------------------\n0x0000000102500000 0x0000000142500000 1.0G 0x0000000641d00000 META|DUP 0/2\n0x0000000142500000 0x0000000182500000 1.0G 0x0000000641d00000 META|DUP 1/2\n0x0000000142500000 0x0000000182500000 1.0G 0x0000000601d00000 META|DUP 0/2\n0x0000000182500000 0x00000001c2500000 1.0G 0x0000000601d00000 META|DUP 1/2\n\nNow how could this possibly happen? All chunk allocation is\n---truncated---"
}
],
"lastModified": "2026-06-24T17:11:04.903",
"configurations": [
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