[moderation] [fs?] KCSAN: data-race in filemap_read / filemap_read (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1dfe225e9af5 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1594e081980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5b9537cd00be479e
dashboard link: https://syzkaller.appspot.com/bug?extid=c2cba7c5a31e3d3b39ff
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org ja...@suse.cz 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/f28c6b5bbba7/disk-1dfe225e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a533cbf38165/vmlinux-1dfe225e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b7013ecdde8d/bzImage-1dfe225e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c2cba7...@syzkaller.appspotmail.com

loop1: detected capacity change from 0 to 1024
==================================================================
BUG: KCSAN: data-race in filemap_read / filemap_read

read to 0xffff88810f790790 of 8 bytes by task 5172 on cpu 0:
filemap_read+0x89/0x690 mm/filemap.c:2601
generic_file_read_iter+0x78/0x340 mm/filemap.c:2806
ext4_file_read_iter+0x1d8/0x2a0
do_iter_readv_writev+0x339/0x3e0
vfs_readv+0x1e5/0x660 fs/read_write.c:932
do_preadv fs/read_write.c:1049 [inline]
__do_sys_preadv2 fs/read_write.c:1111 [inline]
__se_sys_preadv2+0x10c/0x1d0 fs/read_write.c:1102
__x64_sys_preadv2+0x78/0x90 fs/read_write.c:1102
x64_sys_call+0x1a63/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:328
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

write to 0xffff88810f790790 of 8 bytes by task 5171 on cpu 1:
filemap_read+0x615/0x690 mm/filemap.c:2694
generic_file_read_iter+0x78/0x340 mm/filemap.c:2806
ext4_file_read_iter+0x1d8/0x2a0
do_iter_readv_writev+0x339/0x3e0
vfs_readv+0x1e5/0x660 fs/read_write.c:932
do_preadv fs/read_write.c:1049 [inline]
__do_sys_preadv2 fs/read_write.c:1111 [inline]
__se_sys_preadv2+0x10c/0x1d0 fs/read_write.c:1102
__x64_sys_preadv2+0x78/0x90 fs/read_write.c:1102
x64_sys_call+0x1a63/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:328
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: 0xffffffffffffffff -> 0x0000000000000016

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5171 Comm: syz.1.470 Not tainted 6.10.0-rc6-syzkaller-00051-g1dfe225e9af5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================


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