Re: [syzbot] [ocfs2?] KMSAN: uninit-value in _find_next_bit

[syzbot <syzbot+7ea0b96c4ddb49fd1a70@syzkaller.appspotmail.com>]

Hello,

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

(syz.0.16,6650,0):ocfs2_block_check_validate:402 ERROR: CRC32 failed: stored: 0xb3775c19, computed 0x2dd1c265. Applying ECC.
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
=====================================================
BUG: KMSAN: uninit-value in _find_next_bit+0x11c/0x130 lib/find_bit.c:145
 _find_next_bit+0x11c/0x130 lib/find_bit.c:145
 find_next_bit include/linux/find.h:69 [inline]
 ocfs2_add_recovery_chunk fs/ocfs2/quota_local.c:313 [inline]
 ocfs2_recovery_load_quota+0x68e/0x1350 fs/ocfs2/quota_local.c:362
 ocfs2_local_read_info+0x139e/0x2c10 fs/ocfs2/quota_local.c:755
 dquot_load_quota_sb+0xa35/0xdc0 fs/quota/dquot.c:2459
 dquot_load_quota_inode+0x662/0x9f0 fs/quota/dquot.c:2496
 ocfs2_enable_quotas+0x1d4/0x6e0 fs/ocfs2/super.c:930
 ocfs2_fill_super+0xa6b7/0xb550 fs/ocfs2/super.c:1140
 get_tree_bdev_flags+0x6ec/0x910 fs/super.c:1636
 get_tree_bdev+0x37/0x50 fs/super.c:1659
 ocfs2_get_tree+0x34/0x40 fs/ocfs2/super.c:1184
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
 path_mount+0x742/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x71f/0x800 fs/namespace.c:4088
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
 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:
 slab_post_alloc_hook mm/slub.c:4121 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_noprof+0x923/0x1230 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 ocfs2_add_recovery_chunk fs/ocfs2/quota_local.c:305 [inline]
 ocfs2_recovery_load_quota+0x404/0x1350 fs/ocfs2/quota_local.c:362
 ocfs2_local_read_info+0x139e/0x2c10 fs/ocfs2/quota_local.c:755
 dquot_load_quota_sb+0xa35/0xdc0 fs/quota/dquot.c:2459
 dquot_load_quota_inode+0x662/0x9f0 fs/quota/dquot.c:2496
 ocfs2_enable_quotas+0x1d4/0x6e0 fs/ocfs2/super.c:930
 ocfs2_fill_super+0xa6b7/0xb550 fs/ocfs2/super.c:1140
 get_tree_bdev_flags+0x6ec/0x910 fs/super.c:1636
 get_tree_bdev+0x37/0x50 fs/super.c:1659
 ocfs2_get_tree+0x34/0x40 fs/ocfs2/super.c:1184
 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
 path_mount+0x742/0x1f10 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x71f/0x800 fs/namespace.c:4088
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
 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: 6650 Comm: syz.0.16 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
=====================================================


Tested on:

commit:         586de923 Merge tag 'i2c-for-6.14-rc8' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=157bfe98580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1d4644c4063c5098
dashboard link: https://syzkaller.appspot.com/bug?extid=7ea0b96c4ddb49fd1a70
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1613fe98580000