[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_btree_node_get

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 445d9f05fa14 Merge tag 'nfsd-6.13' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112afff7980000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5486b9d7cc64830
dashboard link: https://syzkaller.appspot.com/bug?extid=2b2046c73fcb7e6a0e4e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7024ceac9339/disk-445d9f05.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ebf50afbcd15/vmlinux-445d9f05.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e60e080ed9e/bzImage-445d9f05.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2b2046...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in bch2_btree_node_get+0x605/0x18b0 fs/bcachefs/btree_cache.c:1180
bch2_btree_node_get+0x605/0x18b0 fs/bcachefs/btree_cache.c:1180
btree_path_down fs/bcachefs/btree_iter.c:956 [inline]
bch2_btree_path_traverse_one+0x2c34/0x47b0 fs/bcachefs/btree_iter.c:1182
bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
bch2_btree_iter_peek_node+0x2c5/0x15d0 fs/bcachefs/btree_iter.c:1901
async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2218 [inline]
async_btree_node_rewrite_work+0x29d/0x1710 fs/bcachefs/btree_update_interior.c:2249
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
memcpy_u64s_small fs/bcachefs/util.h:393 [inline]
bkey_reassemble fs/bcachefs/bkey.h:513 [inline]
bch2_bkey_buf_reassemble fs/bcachefs/bkey_buf.h:28 [inline]
btree_node_iter_and_journal_peek+0x866/0x2520 fs/bcachefs/btree_iter.c:898
btree_path_down fs/bcachefs/btree_iter.c:927 [inline]
bch2_btree_path_traverse_one+0x254c/0x47b0 fs/bcachefs/btree_iter.c:1182
bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
bch2_btree_iter_peek_node+0x2c5/0x15d0 fs/bcachefs/btree_iter.c:1901
async_btree_node_rewrite_trans fs/bcachefs/btree_update_interior.c:2218 [inline]
async_btree_node_rewrite_work+0x29d/0x1710 fs/bcachefs/btree_update_interior.c:2249
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
___kmalloc_large_node+0x22c/0x370 mm/slub.c:4238
__kmalloc_large_node_noprof+0x3f/0x1e0 mm/slub.c:4255
__do_kmalloc_node mm/slub.c:4271 [inline]
__kmalloc_node_noprof+0xc96/0x1250 mm/slub.c:4289
__kvmalloc_node_noprof+0xc0/0x2d0 mm/util.c:650
btree_node_data_alloc fs/bcachefs/btree_cache.c:153 [inline]
bch2_btree_node_mem_alloc+0xa72/0x2ee0 fs/bcachefs/btree_cache.c:832
__bch2_btree_node_alloc fs/bcachefs/btree_update_interior.c:321 [inline]
bch2_btree_reserve_get+0x37f/0x2290 fs/bcachefs/btree_update_interior.c:549
bch2_btree_update_start+0x1af9/0x2d60 fs/bcachefs/btree_update_interior.c:1247
bch2_btree_split_leaf+0x120/0xc00 fs/bcachefs/btree_update_interior.c:1856
bch2_trans_commit_error+0x1c0/0x1d60 fs/bcachefs/btree_trans_commit.c:942
__bch2_trans_commit+0x210f/0xd190 fs/bcachefs/btree_trans_commit.c:1140
bch2_trans_commit fs/bcachefs/btree_update.h:184 [inline]
bch2_journal_replay+0x2e3d/0x4d30 fs/bcachefs/recovery.c:317
bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:191 [inline]
bch2_run_recovery_passes+0xaf9/0xf80 fs/bcachefs/recovery_passes.c:244
bch2_fs_recovery+0x447b/0x5b00 fs/bcachefs/recovery.c:861
bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1037
bch2_fs_get_tree+0x13ea/0x22d0 fs/bcachefs/fs.c:2170
vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
do_new_mount+0x71f/0x15e0 fs/namespace.c:3507
path_mount+0x742/0x1f10 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount+0x722/0x810 fs/namespace.c:4034
__ia32_sys_mount+0xe3/0x150 fs/namespace.c:4034
ia32_sys_call+0x260e/0x4180 arch/x86/include/generated/asm/syscalls_32.h:22
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 0 UID: 0 PID: 7199 Comm: kworker/u8:2 Tainted: G W 6.12.0-syzkaller-09734-g445d9f05fa14 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btree_node_rewrite async_btree_node_rewrite_work
=====================================================


---
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 syzk...@googlegroups.com.

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 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