[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_inode_unpack

[syzbot] [bcachefs?] KMSAN: uninit-value in bch2_inode_unpack

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    7367539ad4b0 Merge tag 'cxl-fixes-6.9-rc7' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1553b31f180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bbf567496022057b
dashboard link: https://syzkaller.appspot.com/bug?extid=c123a98c7445baffb168
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/44fb709c4e9c/disk-7367539a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d25971073eca/vmlinux-7367539a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a327aa91b63e/bzImage-7367539a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c123a98c7445baffb168@syzkaller.appspotmail.com

bcachefs (loop4): done starting filesystem
=====================================================
BUG: KMSAN: uninit-value in bch2_inode_unpack_v3 fs/bcachefs/inode.c:270 [inline]
BUG: KMSAN: uninit-value in bch2_inode_unpack+0xaf0/0x4c40 fs/bcachefs/inode.c:323
 bch2_inode_unpack_v3 fs/bcachefs/inode.c:270 [inline]
 bch2_inode_unpack+0xaf0/0x4c40 fs/bcachefs/inode.c:323
 bch2_inode_peek_nowarn+0x4ec/0x5a0 fs/bcachefs/inode.c:351
 bch2_inode_peek fs/bcachefs/inode.c:366 [inline]
 bch2_inode_find_by_inum_trans+0xb3/0x3d0 fs/bcachefs/inode.c:949
 bch2_inode_find_by_inum+0x17b/0x4f0 fs/bcachefs/inode.c:958
 bchfs_truncate+0x437/0x1420 fs/bcachefs/fs-io.c:421
 bch2_setattr+0x29f/0x2f0 fs/bcachefs/fs.c:882
 notify_change+0x1a07/0x1af0 fs/attr.c:497
 do_truncate+0x22a/0x2b0 fs/open.c:65
 handle_truncate fs/namei.c:3300 [inline]
 do_open fs/namei.c:3646 [inline]
 path_openat+0x50d9/0x5b00 fs/namei.c:3799
 do_filp_open+0x20e/0x590 fs/namei.c:3826
 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 stored to memory at:
 memcpy_u64s_small fs/bcachefs/util.h:511 [inline]
 bkey_reassemble fs/bcachefs/bkey.h:505 [inline]
 btree_key_cache_fill fs/bcachefs/btree_key_cache.c:454 [inline]
 bch2_btree_path_traverse_cached_slowpath+0x5f02/0x79f0 fs/bcachefs/btree_key_cache.c:530
 bch2_btree_path_traverse_cached+0xd1a/0x1140
 bch2_btree_path_traverse_one+0x737/0x5290 fs/bcachefs/btree_iter.c:1155
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:225 [inline]
 bch2_btree_iter_peek_slot+0x128c/0x3840 fs/bcachefs/btree_iter.c:2473
 __bch2_bkey_get_iter fs/bcachefs/btree_iter.h:549 [inline]
 bch2_bkey_get_iter fs/bcachefs/btree_iter.h:563 [inline]
 bch2_inode_peek_nowarn+0x208/0x5a0 fs/bcachefs/inode.c:340
 bch2_inode_peek fs/bcachefs/inode.c:366 [inline]
 bch2_inode_find_by_inum_trans+0xb3/0x3d0 fs/bcachefs/inode.c:949
 bch2_inode_find_by_inum+0x17b/0x4f0 fs/bcachefs/inode.c:958
 bchfs_truncate+0x437/0x1420 fs/bcachefs/fs-io.c:421
 bch2_setattr+0x29f/0x2f0 fs/bcachefs/fs.c:882
 notify_change+0x1a07/0x1af0 fs/attr.c:497
 do_truncate+0x22a/0x2b0 fs/open.c:65
 handle_truncate fs/namei.c:3300 [inline]
 do_open fs/namei.c:3646 [inline]
 path_openat+0x50d9/0x5b00 fs/namei.c:3799
 do_filp_open+0x20e/0x590 fs/namei.c:3826
 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: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]
 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+0x7adb/0x9310 fs/bcachefs/recovery.c:785
 bch2_fs_start+0x7b2/0xbd0 fs/bcachefs/super.c:1043
 bch2_fs_open+0x135f/0x1670 fs/bcachefs/super.c:2102
 bch2_mount+0x90d/0x1d90 fs/bcachefs/fs.c:1903
 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: 9730 Comm: syz-executor.4 Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


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