[moderation] [exfat?] KCSAN: data-race in __mark_inode_dirty / __mark_inode_dirty (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0fc810ae3ae1 x86/uaccess: Avoid barrier_nospec() in 64-bit..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1229ae87980000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b957b77e265904d
dashboard link: https://syzkaller.appspot.com/bug?extid=726ac173fbb57fd1459d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [hiro...@mail.parknet.co.jp linki...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org sj155...@samsung.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/783ba9f7a493/disk-0fc810ae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/63fd722bf9ee/vmlinux-0fc810ae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9d8362255e4b/bzImage-0fc810ae.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+726ac1...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / __mark_inode_dirty

write to 0xffff8881066fd928 of 4 bytes by task 24464 on cpu 1:
__mark_inode_dirty+0x24e/0x7e0 fs/fs-writeback.c:2524
mark_buffer_dirty+0x165/0x250 fs/buffer.c:1205
__block_commit_write fs/buffer.c:2194 [inline]
block_write_end+0x123/0x210 fs/buffer.c:2270
generic_write_end+0x5c/0x160 fs/buffer.c:2284
fat_write_end+0x4e/0x160 fs/fat/inode.c:242
generic_perform_write+0x33c/0x4a0 mm/filemap.c:4069
__generic_file_write_iter+0xa1/0x120 mm/filemap.c:4155
generic_file_write_iter+0x77/0x1c0 mm/filemap.c:4181
iter_file_splice_write+0x5f1/0x980 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x160/0x2c0 fs/splice.c:1164
splice_direct_to_actor+0x302/0x670 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x39b/0x970 fs/read_write.c:1388
__do_sys_sendfile64 fs/read_write.c:1455 [inline]
__se_sys_sendfile64 fs/read_write.c:1441 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881066fd928 of 4 bytes by task 24467 on cpu 0:
__mark_inode_dirty+0x58/0x7e0 fs/fs-writeback.c:2475
fat_update_time+0x1f5/0x210 fs/fat/misc.c:357
inode_update_time fs/inode.c:2055 [inline]
touch_atime+0x14f/0x350 fs/inode.c:2128
file_accessed include/linux/fs.h:2528 [inline]
filemap_splice_read+0x8a5/0x910 mm/filemap.c:2977
do_splice_read fs/splice.c:985 [inline]
splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x39b/0x970 fs/read_write.c:1388
__do_sys_sendfile64 fs/read_write.c:1455 [inline]
__se_sys_sendfile64 fs/read_write.c:1441 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000008 -> 0x00000038

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 24467 Comm: syz.7.6616 Not tainted 6.12.0-rc5-syzkaller-00063-g0fc810ae3ae1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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