ghsa-xr82-8hm6-h468
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
btrfs: don't abort filesystem when attempting to snapshot deleted subvolume
If the source file descriptor to the snapshot ioctl refers to a deleted subvolume, we get the following abort:
BTRFS: Transaction aborted (error -2)
WARNING: CPU: 0 PID: 833 at fs/btrfs/transaction.c:1875 create_pending_snapshot+0x1040/0x1190 [btrfs]
Modules linked in: pata_acpi btrfs ata_piix libata scsi_mod virtio_net blake2b_generic xor net_failover virtio_rng failover scsi_common rng_core raid6_pq libcrc32c
CPU: 0 PID: 833 Comm: t_snapshot_dele Not tainted 6.7.0-rc6 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:create_pending_snapshot+0x1040/0x1190 [btrfs]
RSP: 0018:ffffa09c01337af8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff9982053e7c78 RCX: 0000000000000027
RDX: ffff99827dc20848 RSI: 0000000000000001 RDI: ffff99827dc20840
RBP: ffffa09c01337c00 R08: 0000000000000000 R09: ffffa09c01337998
R10: 0000000000000003 R11: ffffffffb96da248 R12: fffffffffffffffe
R13: ffff99820535bb28 R14: ffff99820b7bd000 R15: ffff99820381ea80
FS: 00007fe20aadabc0(0000) GS:ffff99827dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559a120b502f CR3: 00000000055b6000 CR4: 00000000000006f0
Call Trace:
This happens because create_pending_snapshot() initializes the new root item as a copy of the source root item. This includes the refs field, which is 0 for a deleted subvolume. The call to btrfs_insert_root() therefore inserts a root with refs == 0. btrfs_get_new_fs_root() then finds the root and returns -ENOENT if refs == 0, which causes create_pending_snapshot() to abort.
Fix it by checking the source root's refs before attempting the snapshot, but after locking subvol_sem to avoid racing with deletion.
{
"affected": [],
"aliases": [
"CVE-2024-26644"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-03-26T16:15:12Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: don\u0027t abort filesystem when attempting to snapshot deleted subvolume\n\nIf the source file descriptor to the snapshot ioctl refers to a deleted\nsubvolume, we get the following abort:\n\n BTRFS: Transaction aborted (error -2)\n WARNING: CPU: 0 PID: 833 at fs/btrfs/transaction.c:1875 create_pending_snapshot+0x1040/0x1190 [btrfs]\n Modules linked in: pata_acpi btrfs ata_piix libata scsi_mod virtio_net blake2b_generic xor net_failover virtio_rng failover scsi_common rng_core raid6_pq libcrc32c\n CPU: 0 PID: 833 Comm: t_snapshot_dele Not tainted 6.7.0-rc6 #2\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014\n RIP: 0010:create_pending_snapshot+0x1040/0x1190 [btrfs]\n RSP: 0018:ffffa09c01337af8 EFLAGS: 00010282\n RAX: 0000000000000000 RBX: ffff9982053e7c78 RCX: 0000000000000027\n RDX: ffff99827dc20848 RSI: 0000000000000001 RDI: ffff99827dc20840\n RBP: ffffa09c01337c00 R08: 0000000000000000 R09: ffffa09c01337998\n R10: 0000000000000003 R11: ffffffffb96da248 R12: fffffffffffffffe\n R13: ffff99820535bb28 R14: ffff99820b7bd000 R15: ffff99820381ea80\n FS: 00007fe20aadabc0(0000) GS:ffff99827dc00000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000559a120b502f CR3: 00000000055b6000 CR4: 00000000000006f0\n Call Trace:\n \u003cTASK\u003e\n ? create_pending_snapshot+0x1040/0x1190 [btrfs]\n ? __warn+0x81/0x130\n ? create_pending_snapshot+0x1040/0x1190 [btrfs]\n ? report_bug+0x171/0x1a0\n ? handle_bug+0x3a/0x70\n ? exc_invalid_op+0x17/0x70\n ? asm_exc_invalid_op+0x1a/0x20\n ? create_pending_snapshot+0x1040/0x1190 [btrfs]\n ? create_pending_snapshot+0x1040/0x1190 [btrfs]\n create_pending_snapshots+0x92/0xc0 [btrfs]\n btrfs_commit_transaction+0x66b/0xf40 [btrfs]\n btrfs_mksubvol+0x301/0x4d0 [btrfs]\n btrfs_mksnapshot+0x80/0xb0 [btrfs]\n __btrfs_ioctl_snap_create+0x1c2/0x1d0 [btrfs]\n btrfs_ioctl_snap_create_v2+0xc4/0x150 [btrfs]\n btrfs_ioctl+0x8a6/0x2650 [btrfs]\n ? kmem_cache_free+0x22/0x340\n ? do_sys_openat2+0x97/0xe0\n __x64_sys_ioctl+0x97/0xd0\n do_syscall_64+0x46/0xf0\n entry_SYSCALL_64_after_hwframe+0x6e/0x76\n RIP: 0033:0x7fe20abe83af\n RSP: 002b:00007ffe6eff1360 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\n RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fe20abe83af\n RDX: 00007ffe6eff23c0 RSI: 0000000050009417 RDI: 0000000000000003\n RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fe20ad16cd0\n R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\n R13: 00007ffe6eff13c0 R14: 00007fe20ad45000 R15: 0000559a120b6d58\n \u003c/TASK\u003e\n ---[ end trace 0000000000000000 ]---\n BTRFS: error (device vdc: state A) in create_pending_snapshot:1875: errno=-2 No such entry\n BTRFS info (device vdc: state EA): forced readonly\n BTRFS warning (device vdc: state EA): Skipping commit of aborted transaction.\n BTRFS: error (device vdc: state EA) in cleanup_transaction:2055: errno=-2 No such entry\n\nThis happens because create_pending_snapshot() initializes the new root\nitem as a copy of the source root item. This includes the refs field,\nwhich is 0 for a deleted subvolume. The call to btrfs_insert_root()\ntherefore inserts a root with refs == 0. btrfs_get_new_fs_root() then\nfinds the root and returns -ENOENT if refs == 0, which causes\ncreate_pending_snapshot() to abort.\n\nFix it by checking the source root\u0027s refs before attempting the\nsnapshot, but after locking subvol_sem to avoid racing with deletion.",
"id": "GHSA-xr82-8hm6-h468",
"modified": "2024-06-26T00:31:35Z",
"published": "2024-03-26T18:32:05Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26644"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0877497dc97834728e1b528ddf1e1c484292c29c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2bdf872bcfe629a6202ffd6641615a8ed00e8464"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6e6bca99e8d88d989a7cde4c064abea552d5219b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7081929ab2572920e94d70be3d332e5c9f97095a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d8680b722f0ff6d7a01ddacc1844e0d52354d6ff"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ec794a7528199e1be6d47bec03f4755aa75df256"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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