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: [email protected] 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 ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at [email protected]. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
