linux-kernel - [syzbot] [exfat?] KMSAN: uninit-value in exfat_set_entry

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Date:   Wed, 29 Nov 2023 08:28:22 -0800
From:   syzbot <syzbot+d41ef22a1e1ce5b449b2@...kaller.appspotmail.com>
To:     linkinjeon@...nel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, sj1557.seo@...sung.com,
        syzkaller-bugs@...glegroups.com
Subject: [syzbot] [exfat?] KMSAN: uninit-value in exfat_set_entry_time

Hello,

syzbot found the following issue on:

HEAD commit:    305230142ae0 Merge tag 'pm-6.7-rc1-2' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155bcf18e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=956549bd1d1e9efd
dashboard link: https://syzkaller.appspot.com/bug?extid=d41ef22a1e1ce5b449b2
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16a813d08871/disk-30523014.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/226b88790aa7/vmlinux-30523014.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b1b45d0d85fa/bzImage-30523014.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d41ef22a1e1ce5b449b2@...kaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in exfat_set_entry_time+0x2dc/0x320 fs/exfat/misc.c:99
 exfat_set_entry_time+0x2dc/0x320 fs/exfat/misc.c:99
 __exfat_write_inode+0x7ca/0xdd0 fs/exfat/inode.c:59
 exfat_write_inode+0xd9/0x180 fs/exfat/inode.c:97
 write_inode fs/fs-writeback.c:1473 [inline]
 __writeback_single_inode+0x843/0x12b0 fs/fs-writeback.c:1690
 writeback_sb_inodes+0xb73/0x1c00 fs/fs-writeback.c:1916
 wb_writeback+0x4a1/0xdf0 fs/fs-writeback.c:2092
 wb_do_writeback fs/fs-writeback.c:2239 [inline]
 wb_workfn+0x3a4/0x1710 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2703
 worker_thread+0xf45/0x1490 kernel/workqueue.c:2784
 kthread+0x3ed/0x540 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Local variable ts created at:
 __exfat_write_inode+0x105/0xdd0 fs/exfat/inode.c:29
 exfat_write_inode+0xd9/0x180 fs/exfat/inode.c:97

CPU: 1 PID: 8475 Comm: kworker/u4:5 Not tainted 6.6.0-syzkaller-15365-g305230142ae0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: writeback wb_workfn (flush-7:4)
=====================================================


---
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