ghsa-qg2w-5gv5-2cf4
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
btrfs: always do the basic checks for btrfs_qgroup_inherit structure
[BUG] Syzbot reports the following regression detected by KASAN:
BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277 Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171
CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
And it also pinned it down to commit b5357cb268c4 ("btrfs: qgroup: do not check qgroup inherit if qgroup is disabled").
[CAUSE] That offending commit skips the whole qgroup inherit check if qgroup is not enabled.
But that also skips the very basic checks like num_ref_copies/num_excl_copies and the structure size checks.
Meaning if a qgroup enable/disable race is happening at the background, and we pass a btrfs_qgroup_inherit structure when the qgroup is disabled, the check would be completely skipped.
Then at the time of transaction commitment, qgroup is re-enabled and btrfs_qgroup_inherit() is going to use the incorrect structure and causing the above KASAN error.
[FIX] Make btrfs_qgroup_check_inherit() only skip the source qgroup checks. So that even if invalid btrfs_qgroup_inherit structure is passed in, we can still reject invalid ones no matter if qgroup is enabled or not.
Furthermore we do already have an extra safety inside btrfs_qgroup_inherit(), which would just ignore invalid qgroup sources, so even if we only skip the qgroup source check we're still safe.
{
"affected": [],
"aliases": [
"CVE-2024-42111"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-30T08:15:03Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: always do the basic checks for btrfs_qgroup_inherit structure\n\n[BUG]\nSyzbot reports the following regression detected by KASAN:\n\n BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277\n Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171\n\n CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024\n Call Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277\n create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854\n create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922\n btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382\n create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875\n btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029\n btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075\n __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340\n btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422\n btrfs_ioctl+0x99e/0xc60\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7fcbf1992509\n RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\n RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509\n RDX: 0000000020000280 RSI: 0000000050009417 RDI: 0000000000000003\n RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbf19eb660\n R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e\n \u003c/TASK\u003e\n\nAnd it also pinned it down to commit b5357cb268c4 (\"btrfs: qgroup: do not\ncheck qgroup inherit if qgroup is disabled\").\n\n[CAUSE]\nThat offending commit skips the whole qgroup inherit check if qgroup is\nnot enabled.\n\nBut that also skips the very basic checks like\nnum_ref_copies/num_excl_copies and the structure size checks.\n\nMeaning if a qgroup enable/disable race is happening at the background,\nand we pass a btrfs_qgroup_inherit structure when the qgroup is\ndisabled, the check would be completely skipped.\n\nThen at the time of transaction commitment, qgroup is re-enabled and\nbtrfs_qgroup_inherit() is going to use the incorrect structure and\ncausing the above KASAN error.\n\n[FIX]\nMake btrfs_qgroup_check_inherit() only skip the source qgroup checks.\nSo that even if invalid btrfs_qgroup_inherit structure is passed in, we\ncan still reject invalid ones no matter if qgroup is enabled or not.\n\nFurthermore we do already have an extra safety inside\nbtrfs_qgroup_inherit(), which would just ignore invalid qgroup sources,\nso even if we only skip the qgroup source check we\u0027re still safe.",
"id": "GHSA-qg2w-5gv5-2cf4",
"modified": "2024-07-30T09:31:51Z",
"published": "2024-07-30T09:31:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-42111"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/724d8042cef84496ddb4492dc120291f997ae26b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ebe5ea02577b2c527958af1b76ac472c7ab53a56"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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