From: syzbot <syzbot+377f67f96ce8b673a57b@syzkaller.appspotmail.com>
To: kent.overstreet@linux.dev, linux-bcachefs@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [bcachefs?] KMSAN: uninit-value in bch2_check_subvols
Date: Tue, 01 Jul 2025 12:20:33 -0700 [thread overview]
Message-ID: <68643501.a70a0220.3b7e22.1f46.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: d0b3b7b22dfa Linux 6.16-rc4
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14b3b88c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1d5c61bcebaf295a
dashboard link: https://syzkaller.appspot.com/bug?extid=377f67f96ce8b673a57b
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14a76770580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10db988c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/20baa44346a0/disk-d0b3b7b2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8b99eb399d29/vmlinux-d0b3b7b2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ccabd4354061/bzImage-d0b3b7b2.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/f1f67d5353ee/mount_2.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+377f67f96ce8b673a57b@syzkaller.appspotmail.com
bcachefs (loop2): bucket_gens_init... done
bcachefs (loop2): check_snapshot_trees... done
bcachefs (loop2): check_snapshots...
done
bcachefs (loop2): check_subvols...
=====================================================
BUG: KMSAN: uninit-value in check_subvol fs/bcachefs/subvolume.c:76 [inline]
BUG: KMSAN: uninit-value in bch2_check_subvols+0x1297/0x48c0 fs/bcachefs/subvolume.c:187
check_subvol fs/bcachefs/subvolume.c:76 [inline]
bch2_check_subvols+0x1297/0x48c0 fs/bcachefs/subvolume.c:187
bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:484 [inline]
__bch2_run_recovery_passes+0x49e/0x1330 fs/bcachefs/recovery_passes.c:539
bch2_run_recovery_passes+0x284/0x310 fs/bcachefs/recovery_passes.c:610
bch2_fs_recovery+0x53bf/0x66d0 fs/bcachefs/recovery.c:1039
bch2_fs_start+0x1159/0x1920 fs/bcachefs/super.c:1212
bch2_fs_get_tree+0x113a/0x2ae0 fs/bcachefs/fs.c:2490
vfs_get_tree+0xb3/0x5c0 fs/super.c:1804
do_new_mount+0x738/0x1610 fs/namespace.c:3902
path_mount+0x6db/0x1e90 fs/namespace.c:4226
do_mount fs/namespace.c:4239 [inline]
__do_sys_mount fs/namespace.c:4450 [inline]
__se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427
__x64_sys_mount+0xe4/0x150 fs/namespace.c:4427
x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
___kmalloc_large_node+0x2e2/0x460 mm/slub.c:4283
__kmalloc_large_node_noprof+0x3f/0x1f0 mm/slub.c:4300
__do_kmalloc_node mm/slub.c:4316 [inline]
__kvmalloc_node_noprof+0x9f/0x1530 mm/slub.c:5015
btree_node_data_alloc+0xe2/0x5f0 fs/bcachefs/btree_cache.c:150
__bch2_btree_node_mem_alloc+0x1eb/0x880 fs/bcachefs/btree_cache.c:195
bch2_fs_btree_cache_init+0x4fc/0xd20 fs/bcachefs/btree_cache.c:656
bch2_fs_alloc fs/bcachefs/super.c:998 [inline]
bch2_fs_open+0x46ac/0x54e0 fs/bcachefs/super.c:2432
bch2_fs_get_tree+0x955/0x2ae0 fs/bcachefs/fs.c:2474
vfs_get_tree+0xb3/0x5c0 fs/super.c:1804
do_new_mount+0x738/0x1610 fs/namespace.c:3902
path_mount+0x6db/0x1e90 fs/namespace.c:4226
do_mount fs/namespace.c:4239 [inline]
__do_sys_mount fs/namespace.c:4450 [inline]
__se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4427
__x64_sys_mount+0xe4/0x150 fs/namespace.c:4427
x64_sys_call+0xfa7/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 1 UID: 0 PID: 6242 Comm: syz.2.21 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(undef)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
=====================================================
---
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reply other threads:[~2025-07-01 19:20 UTC|newest]
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