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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    feffde684ac2 Merge tag 'for-6.13-rc1-tag' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=130d90f8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=96ee18b6611821ab
dashboard link: https://syzkaller.appspot.com/bug?extid=79f640f4f94cdd55a406
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/b31883c9ce49/disk-feffde68.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cd0fe66ddb61/vmlinux-feffde68.xz
kernel image: https://storage.googleapis.com/syzbot-assets/88e3455fb342/bzImage-feffde68.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+79f640f4f94cdd55a406@xxxxxxxxxxxxxxxxxxxxxxxxx

=====================================================
BUG: KMSAN: uninit-value in rw_aux_tree_insert_entry+0x557/0x970 fs/bcachefs/bset.c:904
 rw_aux_tree_insert_entry+0x557/0x970 fs/bcachefs/bset.c:904
 bch2_bset_fix_lookup_table+0xecc/0x13e0
 bch2_bset_insert+0x1621/0x19f0 fs/bcachefs/bset.c:1015
 bch2_btree_bset_insert_key+0xf4e/0x2b60 fs/bcachefs/btree_trans_commit.c:217
 bch2_btree_insert_key_leaf+0x276/0x1050 fs/bcachefs/btree_trans_commit.c:300
 wb_flush_one fs/bcachefs/btree_write_buffer.c:186 [inline]
 bch2_btree_write_buffer_flush_locked+0x47c1/0x7090 fs/bcachefs/btree_write_buffer.c:379
 btree_write_buffer_flush_seq+0x2ec7/0x30b0 fs/bcachefs/btree_write_buffer.c:517
 bch2_btree_write_buffer_flush_going_ro+0x1a7/0x2d0 fs/bcachefs/btree_write_buffer.c:556
 __bch2_fs_read_only+0x1c6/0xb40 fs/bcachefs/super.c:275
 bch2_fs_read_only+0xd2c/0x15d0 fs/bcachefs/super.c:356
 __bch2_fs_stop+0xf0/0xf10 fs/bcachefs/super.c:621
 bch2_fs_stop+0x1e/0x30 fs/bcachefs/super.c:678
 bch2_fs_get_tree+0x1dff/0x22d0 fs/bcachefs/fs.c:2265
 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
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4034
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

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+0x2be/0xa80 fs/bcachefs/btree_cache.c:198
 bch2_fs_btree_cache_init+0x4e4/0xb50 fs/bcachefs/btree_cache.c:653
 bch2_fs_alloc fs/bcachefs/super.c:917 [inline]
 bch2_fs_open+0x4d3a/0x5b40 fs/bcachefs/super.c:2065
 bch2_fs_get_tree+0x983/0x22d0 fs/bcachefs/fs.c:2157
 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
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4034
 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 10623 Comm: syz.6.1178 Tainted: G        W          6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================


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