{"cve":"CVE-2026-45934","nvd":{"published":"2026-05-27T14:17:09.480","modified":"2026-10-21T13:19:00.280","status":"Undergoing Analysis","description":"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---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/09207c3975e1f8f76a52472004dfcab997b4cbd6","https://git.kernel.org/stable/c/12addb8ab5eec94098d4c7c6614830ccbe7ad130","https://git.kernel.org/stable/c/156cac365e27a82b64ae510c5f463fd81f0265b1","https://git.kernel.org/stable/c/7d4eadee7042d27fcea659fcdd738f463a7d2e70","https://git.kernel.org/stable/c/b14c5e04bd0f722ed631845599d52d03fcae1bc1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-45934","score":0.00155,"percentile":0.04561,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}