[moderation] [fs?] KCSAN: data-race in filemap_read / filemap_read (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 55cb5f43689d Merge tag 'trace-v6.7-rc6' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1521278ee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=989a728d0f884055
dashboard link: https://syzkaller.appspot.com/bug?extid=40ccd616d7c46b368c0f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/48e180dd5134/disk-55cb5f43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8d5228b1803d/vmlinux-55cb5f43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fc03913fb908/bzImage-55cb5f43.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+40ccd6...@syzkaller.appspotmail.com

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

write to 0xffff8881553cbc90 of 8 bytes by task 6072 on cpu 1:
filemap_read+0x605/0x680 mm/filemap.c:2662
generic_file_read_iter+0x78/0x330 mm/filemap.c:2772
ext4_file_read_iter+0x1d8/0x2a0
call_read_iter include/linux/fs.h:2014 [inline]
copy_splice_read+0x26b/0x4b0 fs/splice.c:364
vfs_splice_read fs/splice.c:992 [inline]
splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881553cbc90 of 8 bytes by task 6073 on cpu 0:
filemap_read+0x89/0x680 mm/filemap.c:2569
generic_file_read_iter+0x78/0x330 mm/filemap.c:2772
ext4_file_read_iter+0x1d8/0x2a0
call_read_iter include/linux/fs.h:2014 [inline]
copy_splice_read+0x26b/0x4b0 fs/splice.c:364
vfs_splice_read fs/splice.c:992 [inline]
splice_direct_to_actor+0x2aa/0x690 fs/splice.c:1069
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000002010259 -> 0x000000000201026f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6073 Comm: syz-executor.1 Not tainted 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.