KMSAN: kernel-infoleak in btrfs_ioctl_logical_to

KMSAN: kernel-infoleak in btrfs_ioctl_logical_to_ino (2)

Status: upstream: reported on 2024/04/16 13:14
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+510a1abbb8116eeb341d@syzkaller.appspotmail.com
Fix commit: 2f7ef5bb4a2f btrfs: fix information leak in btrfs_ioctl_logical_to_ino()
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-net-next-test-gce], missing on: [ci-qemu2-riscv64 ci-upstream-gce-arm64 ci2-upstream-usb]
First crash: 14d, last: 14d

▶ ▼ Discussions (1)

Title	Replies (including bot)	Last reply
[syzbot] [btrfs?] KMSAN: kernel-infoleak in btrfs_ioctl_logical_to_ino (2)	1 (2)	2024/04/16 16:56

▶ ▼ Similar bugs (1)

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KMSAN: kernel-infoleak in btrfs_ioctl_logical_to_ino btrfs				6	123d	164d	0/26	auto-obsoleted due to no activity on 2024/03/28 09:38

Sample crash report:

BTRFS info (device loop1): first mount of filesystem c9fe44da-de57-406a-8241-57ec7d4412cf
BTRFS info (device loop1): using crc32c (crc32c-generic) checksum algorithm
BTRFS info (device loop1): using free-space-tree
=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _copy_to_user+0xbc/0x110 lib/usercopy.c:40
 copy_to_user include/linux/uaccess.h:191 [inline]
 btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499
 btrfs_ioctl+0x714/0x1260
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 __kmalloc_large_node+0x231/0x370 mm/slub.c:3921
 __do_kmalloc_node mm/slub.c:3954 [inline]
 __kmalloc_node+0xb07/0x1060 mm/slub.c:3973
 kmalloc_node include/linux/slab.h:648 [inline]
 kvmalloc_node+0xc0/0x2d0 mm/util.c:634
 kvmalloc include/linux/slab.h:766 [inline]
 init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779
 btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480
 btrfs_ioctl+0x714/0x1260
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 40-65535 of 65536 are uninitialized
Memory access of size 65536 starts at ffff888045a40000

CPU: 0 PID: 5428 Comm: syz-executor.1 Not tainted 6.9.0-rc4-syzkaller-00028-gcef27048e5c2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2024/04/16 12:15	upstream	cef27048e5c2	0d592ce4	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci-upstream-kmsan-gce-root	KMSAN: kernel-infoleak in btrfs_ioctl_logical_to_ino

* ~~Struck through~~ repros no longer work on HEAD.