[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_bset_fix_lookup_table

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a5131c3fdf26 Merge tag 'x86-shstk-2024-05-13' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16133182980000
kernel config: https://syzkaller.appspot.com/x/.config?x=64e100d74625a6a5
dashboard link: https://syzkaller.appspot.com/bug?extid=097987693500c9e31552
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/81edac548743/disk-a5131c3f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/42f67aa888e5/vmlinux-a5131c3f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2e5cf5b3704d/bzImage-a5131c3f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+097987...@syzkaller.appspotmail.com

bcachefs (loop0): done starting filesystem
=====================================================
BUG: KMSAN: uninit-value in bch2_bset_fix_lookup_table+0x15e1/0x1e90 fs/bcachefs/bset.c:986
bch2_bset_fix_lookup_table+0x15e1/0x1e90 fs/bcachefs/bset.c:986
bch2_bset_insert+0x1617/0x19f0 fs/bcachefs/bset.c:1042
bch2_btree_bset_insert_key+0xf56/0x2b70 fs/bcachefs/btree_trans_commit.c:194
bch2_btree_insert_key_leaf+0x276/0x1050 fs/bcachefs/btree_trans_commit.c:277
bch2_trans_commit_write_locked fs/bcachefs/btree_trans_commit.c:744 [inline]
do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:854 [inline]
__bch2_trans_commit+0x98e6/0xab10 fs/bcachefs/btree_trans_commit.c:1093
bch2_trans_commit fs/bcachefs/btree_update.h:168 [inline]
__bch2_create+0xe93/0x15d0 fs/bcachefs/fs.c:327
bch2_mknod fs/bcachefs/fs.c:451 [inline]
bch2_create+0xdd/0x1e0 fs/bcachefs/fs.c:465
lookup_open fs/namei.c:3505 [inline]
open_last_lookups fs/namei.c:3574 [inline]
path_openat+0x2d74/0x5b00 fs/namei.c:3804
do_filp_open+0x20e/0x590 fs/namei.c:3834
do_sys_openat2+0x1bf/0x2f0 fs/open.c:1406
do_sys_open fs/open.c:1421 [inline]
__do_sys_openat fs/open.c:1437 [inline]
__se_sys_openat fs/open.c:1432 [inline]
__x64_sys_openat+0x2a1/0x310 fs/open.c:1432
x64_sys_call+0x3a64/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:258
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:3994
__do_kmalloc_node mm/slub.c:4027 [inline]
__kmalloc_node+0xb10/0x10c0 mm/slub.c:4046
kmalloc_node include/linux/slab.h:648 [inline]
kvmalloc_node+0xc0/0x2d0 mm/util.c:634
kvmalloc include/linux/slab.h:766 [inline]
btree_bounce_alloc fs/bcachefs/btree_io.c:118 [inline]
bch2_btree_node_read_done+0x4e68/0x75e0 fs/bcachefs/btree_io.c:1185
btree_node_read_work+0x8a5/0x1eb0 fs/bcachefs/btree_io.c:1324
bch2_btree_node_read+0x3d42/0x4b50
__bch2_btree_root_read fs/bcachefs/btree_io.c:1748 [inline]
bch2_btree_root_read+0xa6c/0x13d0 fs/bcachefs/btree_io.c:1772
read_btree_roots+0x454/0xee0 fs/bcachefs/recovery.c:457
bch2_fs_recovery+0x7b6a/0x93e0 fs/bcachefs/recovery.c:785
bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1043
bch2_fs_open+0x152a/0x15f0 fs/bcachefs/super.c:2105
bch2_mount+0x90d/0x1d90 fs/bcachefs/fs.c:1906
legacy_get_tree+0x114/0x290 fs/fs_context.c:662
vfs_get_tree+0xa7/0x570 fs/super.c:1779
do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
path_mount+0x742/0x1f20 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3875
__x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
x64_sys_call+0x2bf4/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:166
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

CPU: 0 PID: 6538 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-01768-ga5131c3fdf26 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
=====================================================


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