[moderation] [fs?] [mm?] KCSAN: data-race in __filemap_add_folio / invalidate_bdev (10)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 11e7861d680c Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=109d8e34580000
kernel config: https://syzkaller.appspot.com/x/.config?x=52ae2e92d7a28724
dashboard link: https://syzkaller.appspot.com/bug?extid=a7b8f9378c590dcdf33e
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [ak...@linux-foundation.org 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/da1997531bcc/disk-11e7861d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6c7ff50f799f/vmlinux-11e7861d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/46d798b97bdb/bzImage-11e7861d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a7b8f9...@syzkaller.appspotmail.com

EXT4-fs (loop8): ext4_check_descriptors: Inode bitmap for group 0 overlaps block group descriptors
EXT4-fs (loop8): ext4_check_descriptors: Checksum for group 0 failed (51554!=20869)
JBD2: no valid journal superblock found
EXT4-fs (loop8): Could not load journal inode
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / invalidate_bdev

read-write to 0xffff8881005f3778 of 8 bytes by task 3741 on cpu 1:
__filemap_add_folio+0x5b9/0x7d0 mm/filemap.c:928
filemap_add_folio+0x98/0x1b0 mm/filemap.c:969
page_cache_ra_unbounded+0x1f3/0x380 mm/readahead.c:275
do_page_cache_ra mm/readahead.c:327 [inline]
force_page_cache_ra mm/readahead.c:356 [inline]
page_cache_sync_ra+0x256/0x6c0 mm/readahead.c:572
filemap_get_pages+0x2d0/0x1150 mm/filemap.c:2603
filemap_read+0x231/0xa00 mm/filemap.c:2712
blkdev_read_iter+0x22d/0x2e0 block/fops.c:849
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x649/0x770 fs/read_write.c:572
ksys_read+0xda/0x1a0 fs/read_write.c:715
__do_sys_read fs/read_write.c:724 [inline]
__se_sys_read fs/read_write.c:722 [inline]
__x64_sys_read+0x40/0x50 fs/read_write.c:722
x64_sys_call+0x27bc/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881005f3778 of 8 bytes by task 8100 on cpu 0:
invalidate_bdev+0x25/0x70 block/bdev.c:99
__ext4_fill_super fs/ext4/super.c:5703 [inline]
ext4_fill_super+0x2b5d/0x35d0 fs/ext4/super.c:5728
get_tree_bdev_flags+0x291/0x300 fs/super.c:1692
get_tree_bdev+0x1f/0x30 fs/super.c:1715
ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5760
vfs_get_tree+0x54/0x1d0 fs/super.c:1815
do_new_mount+0x207/0x5e0 fs/namespace.c:3808
path_mount+0x4a4/0xb20 fs/namespace.c:4123
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
__x64_sys_mount+0x67/0x80 fs/namespace.c:4324
x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000007 -> 0x0000000000000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8100 Comm: syz.8.1349 Not tainted syzkaller #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================


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[syzbot]

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