Re: [syzbot] [jfs?] KMSAN: uninit-value in BT_STACK_DUMP

syzbot
2025-05-06T13:31:06Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KMSAN: uninit-value in dtSearch

loop0: detected capacity change from 0 to 32768
=====================================================
BUG: KMSAN: uninit-value in UniStrncmp_le fs/jfs/jfs_unicode.h:55 [inline]
BUG: KMSAN: uninit-value in dtCompare fs/jfs/jfs_dtree.c:3340 [inline]
BUG: KMSAN: uninit-value in dtSearch+0x1261/0x3d30 fs/jfs/jfs_dtree.c:650
UniStrncmp_le fs/jfs/jfs_unicode.h:55 [inline]
dtCompare fs/jfs/jfs_dtree.c:3340 [inline]
dtSearch+0x1261/0x3d30 fs/jfs/jfs_dtree.c:650
jfs_lookup+0x18b/0x5a0 fs/jfs/namei.c:1461
lookup_one_qstr_excl_raw+0x204/0x5b0 fs/namei.c:1689
lookup_one_qstr_excl fs/namei.c:1711 [inline]
do_unlinkat+0x2e3/0xe50 fs/namei.c:4631
__do_sys_unlink fs/namei.c:4689 [inline]
__se_sys_unlink fs/namei.c:4687 [inline]
__x64_sys_unlink+0x71/0xb0 fs/namei.c:4687
x64_sys_call+0x29de/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:88
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x1b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
__alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:4993
alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2301
alloc_frozen_pages_noprof+0xf7/0x200 mm/mempolicy.c:2372
alloc_slab_page mm/slub.c:2468 [inline]
allocate_slab+0x24d/0x1210 mm/slub.c:2632
new_slab mm/slub.c:2686 [inline]
___slab_alloc+0xfec/0x3480 mm/slub.c:3872
__slab_alloc mm/slub.c:3962 [inline]
__slab_alloc_node mm/slub.c:4037 [inline]
slab_alloc_node mm/slub.c:4198 [inline]
kmem_cache_alloc_lru_noprof+0x922/0xed0 mm/slub.c:4229
jfs_alloc_inode+0x60/0xf0 fs/jfs/super.c:105
alloc_inode+0x87/0x4a0 fs/inode.c:346
new_inode+0x39/0x460 fs/inode.c:1145
diReadSpecial+0x62/0xb00 fs/jfs/jfs_imap.c:426
jfs_mount+0x760/0x1310 fs/jfs/jfs_mount.c:138
jfs_fill_super+0x8fa/0x1900 fs/jfs/super.c:523
get_tree_bdev_flags+0x6e3/0x920 fs/super.c:1636
get_tree_bdev+0x38/0x50 fs/super.c:1659
jfs_get_tree+0x35/0x40 fs/jfs/super.c:635
vfs_get_tree+0xb0/0x5c0 fs/super.c:1759
do_new_mount+0x73c/0x1620 fs/namespace.c:3881
path_mount+0x6db/0x1e90 fs/namespace.c:4208
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4432 [inline]
__se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4409
__x64_sys_mount+0xe4/0x150 fs/namespace.c:4409
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+0xd9/0x1b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 7043 Comm: syz.0.33 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8-dirty #0 PREEMPT(undef)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
=====================================================

Tested on:

commit: 02ddfb98 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1439c8f4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9dc42c34a3f5c357
dashboard link: https://syzkaller.appspot.com/bug?extid=ba5f49027aace342d24d
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=100ae8f4580000