MIME-Version: 1.0
Date:   Mon, 06 Mar 2023 09:55:44 -0800
Message-ID: <0000000000000d710705f63f014c@google.com>
Subject: [syzbot] [nilfs?] KMSAN: uninit-value in nilfs_add_checksums_on_logs
From:   syzbot <syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com>
To:     glider@google.com, konishi.ryusuke@gmail.com,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-nilfs@vger.kernel.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hello,

syzbot found the following issue on:

HEAD commit:    54b4a7d3d6c6 kmsan: add memsetXX tests
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=143f81e4c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=46c642641b9ef616
dashboard link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b2a457fb4580/disk-54b4a7d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1acddc397ddb/vmlinux-54b4a7d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/eceee3367163/bzImage-54b4a7d3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in crc32_body lib/crc32.c:110 [inline]
BUG: KMSAN: uninit-value in crc32_le_generic lib/crc32.c:179 [inline]
BUG: KMSAN: uninit-value in crc32_le_base+0x446/0xd80 lib/crc32.c:197
 crc32_body lib/crc32.c:110 [inline]
 crc32_le_generic lib/crc32.c:179 [inline]
 crc32_le_base+0x446/0xd80 lib/crc32.c:197
 nilfs_segbuf_fill_in_segsum_crc fs/nilfs2/segbuf.c:182 [inline]
 nilfs_add_checksums_on_logs+0x2ce/0xe30 fs/nilfs2/segbuf.c:320
 nilfs_segctor_do_construct+0xa553/0xe900 fs/nilfs2/segment.c:2076
 nilfs_segctor_construct+0x1eb/0xe30 fs/nilfs2/segment.c:2379
 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline]
 nilfs_segctor_thread+0xc76/0x1240 fs/nilfs2/segment.c:2570
 kthread+0x31f/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Uninit was stored to memory at:
 nilfs_write_dat_node_binfo+0x12c/0x280 fs/nilfs2/segment.c:658
 nilfs_segctor_assign fs/nilfs2/segment.c:1629 [inline]
 nilfs_segctor_do_construct+0x753c/0xe900 fs/nilfs2/segment.c:2056
 nilfs_segctor_construct+0x1eb/0xe30 fs/nilfs2/segment.c:2379
 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2487 [inline]
 nilfs_segctor_thread+0xc76/0x1240 fs/nilfs2/segment.c:2570
 kthread+0x31f/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Local variable binfo.i.i created at:
 nilfs_segctor_update_payload_blocknr fs/nilfs2/segment.c:1562 [inline]
 nilfs_segctor_assign fs/nilfs2/segment.c:1629 [inline]
 nilfs_segctor_do_construct+0x6ac9/0xe900 fs/nilfs2/segment.c:2056
 nilfs_segctor_construct+0x1eb/0xe30 fs/nilfs2/segment.c:2379

CPU: 1 PID: 28393 Comm: segctord Not tainted 6.2.0-syzkaller-81157-g54b4a7d3d6c6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
=====================================================


---
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