[moderation] [mm?] [fs?] KCSAN: data-race in __filemap_add_folio / invalidate_bdev (12)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3dab139d4795 Merge tag 'rust-fixes-7.2-2' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14d1a499580000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b3039e8461eef5
dashboard link: https://syzkaller.appspot.com/bug?extid=e0624b5bf72b99131402
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [ak...@linux-foundation.org ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org linu...@kvack.org wi...@infradead.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/aff374cafa9b/disk-3dab139d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3a180df70f51/vmlinux-3dab139d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/64893717f343/bzImage-3dab139d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e0624b...@syzkaller.appspotmail.com

loop5: detected capacity change from 0 to 8192
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / invalidate_bdev

read-write to 0xffff88810048a378 of 8 bytes by task 4649 on cpu 0:
__filemap_add_folio+0x66e/0x880 mm/filemap.c:919
filemap_add_folio+0x1d3/0x350 mm/filemap.c:966
page_cache_ra_unbounded+0x1a4/0x3a0 mm/readahead.c:293
do_page_cache_ra mm/readahead.c:348 [inline]
force_page_cache_ra+0x190/0x1d0 mm/readahead.c:378
page_cache_sync_ra+0x107/0x510 mm/readahead.c:602
filemap_get_pages+0x2f2/0x1360 mm/filemap.c:2704
filemap_read+0x219/0xa20 mm/filemap.c:2814
blkdev_read_iter+0x21e/0x2d0 block/fops.c:830
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x699/0x7c0 fs/read_write.c:574
ksys_read+0xdc/0x1a0 fs/read_write.c:716
__do_sys_read fs/read_write.c:725 [inline]
__se_sys_read fs/read_write.c:723 [inline]
__x64_sys_read+0x40/0x50 fs/read_write.c:723
x64_sys_call+0x2886/0x3020 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810048a378 of 8 bytes by task 19925 on cpu 1:
invalidate_bdev+0x25/0x70 block/bdev.c:99
bdev_disk_changed+0xe8/0xe20 block/partitions/core.c:659
loop_reread_partitions drivers/block/loop.c:443 [inline]
loop_set_status+0x5af/0x670 drivers/block/loop.c:1268
loop_set_status64 drivers/block/loop.c:1364 [inline]
lo_ioctl+0x66d/0x1390 drivers/block/loop.c:1550
blkdev_ioctl+0x387/0x460 block/ioctl.c:797
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 19925 Comm: syz.5.3651 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
==================================================================
loop5: p1 < > p3 < > p4
loop5: partition table partially beyond EOD, truncated
loop5: p1 start 4294967040 is beyond EOD, truncated
loop5: p4 size 851974 extends beyond EOD, truncated


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