[syzbot] [mm?] [fs?] KCSAN: data-race in __filemap_add_folio / invalidate_bdev (8)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    80e54e84911a Linux 6.14-rc6
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1664a7a8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=958433697845b9a6
dashboard link: https://syzkaller.appspot.com/bug?extid=f2aaf773187f5cae54f3
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e94728c052e3/disk-80e54e84.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742f05e27746/vmlinux-80e54e84.xz
kernel image: https://storage.googleapis.com/syzbot-assets/90d418e775f7/bzImage-80e54e84.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f2aaf773187f5cae54f3@xxxxxxxxxxxxxxxxxxxxxxxxx

EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / invalidate_bdev

read-write to 0xffff888100630570 of 8 bytes by task 3291 on cpu 0:
 __filemap_add_folio+0x430/0x6f0 mm/filemap.c:929
 filemap_add_folio+0x9c/0x1b0 mm/filemap.c:981
 page_cache_ra_unbounded+0x1c1/0x350 mm/readahead.c:276
 do_page_cache_ra mm/readahead.c:328 [inline]
 force_page_cache_ra mm/readahead.c:357 [inline]
 page_cache_sync_ra+0x252/0x680 mm/readahead.c:585
 filemap_get_pages+0x2ca/0x11a0 mm/filemap.c:2580
 filemap_read+0x230/0x8c0 mm/filemap.c:2691
 blkdev_read_iter+0x228/0x2d0 block/fops.c:796
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x5cc/0x6f0 fs/read_write.c:565
 ksys_read+0xe8/0x1b0 fs/read_write.c:708
 __do_sys_read fs/read_write.c:717 [inline]
 __se_sys_read fs/read_write.c:715 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:715
 x64_sys_call+0x2874/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:1
 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 0xffff888100630570 of 8 bytes by task 3306 on cpu 1:
 invalidate_bdev+0x25/0x70 block/bdev.c:99
 ext4_put_super+0x571/0x810 fs/ext4/super.c:1356
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7368
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1413
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1420
 task_work_run+0x13a/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000000000000d -> 0x000000000000000e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3306 Comm: syz-executor Not tainted 6.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================


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