[moderation] [mm?] KCSAN: data-race in munlock_folio / need_mlock_drain (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 83814698cf48 Merge tag 'powerpc-6.10-2' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1192bdfc980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b639694183430f97
dashboard link: https://syzkaller.appspot.com/bug?extid=a8a0b4c9cd4655c8dc58
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/038707734b30/disk-83814698.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cf36293ab620/vmlinux-83814698.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0784378e1d1b/bzImage-83814698.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a8a0b4...@syzkaller.appspotmail.com

loop3: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed nobh option
EXT4-fs (loop3): can't mount with data=, fs mounted w/o journal
==================================================================
BUG: KCSAN: data-race in munlock_folio / need_mlock_drain

read-write to 0xffff888237d2b410 of 1 bytes by task 10647 on cpu 1:
folio_batch_add include/linux/pagevec.h:77 [inline]
munlock_folio+0x42/0x130 mm/mlock.c:301
munlock_vma_folio mm/internal.h:880 [inline]
__folio_remove_rmap mm/rmap.c:1578 [inline]
folio_remove_rmap_ptes+0x220/0x230 mm/rmap.c:1595
zap_present_folio_ptes mm/memory.c:1505 [inline]
zap_present_ptes mm/memory.c:1570 [inline]
zap_pte_range mm/memory.c:1612 [inline]
zap_pmd_range mm/memory.c:1730 [inline]
zap_pud_range mm/memory.c:1759 [inline]
zap_p4d_range mm/memory.c:1780 [inline]
unmap_page_range+0x1016/0x23f0 mm/memory.c:1801
unmap_single_vma+0x142/0x1d0 mm/memory.c:1847
unmap_vmas+0x18d/0x2b0 mm/memory.c:1891
exit_mmap+0x18f/0x710 mm/mmap.c:3341
__mmput+0x28/0x1c0 kernel/fork.c:1346
mmput+0x4c/0x60 kernel/fork.c:1368
exit_mm+0xe4/0x190 kernel/exit.c:565
do_exit+0x556/0x1710 kernel/exit.c:861
do_group_exit+0x102/0x150 kernel/exit.c:1023
get_signal+0xf2f/0x1080 kernel/signal.c:2909
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d2b410 of 1 bytes by task 10686 on cpu 0:
folio_batch_count include/linux/pagevec.h:56 [inline]
need_mlock_drain+0x30/0x50 mm/mlock.c:235
cpu_needs_drain mm/swap.c:806 [inline]
__lru_add_drain_all+0x235/0x410 mm/swap.c:894
lru_add_drain_all+0x10/0x20 mm/swap.c:910
invalidate_bdev+0x47/0x70 block/bdev.c:100
__ext4_fill_super fs/ext4/super.c:5651 [inline]
ext4_fill_super+0x6f3/0x39e0 fs/ext4/super.c:5676
get_tree_bdev+0x253/0x2e0 fs/super.c:1615
ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5708
vfs_get_tree+0x56/0x1d0 fs/super.c:1780
do_new_mount+0x227/0x690 fs/namespace.c:3352
path_mount+0x49b/0xb30 fs/namespace.c:3679
do_mount fs/namespace.c:3692 [inline]
__do_sys_mount fs/namespace.c:3898 [inline]
__se_sys_mount+0x27f/0x2d0 fs/namespace.c:3875
__x64_sys_mount+0x67/0x80 fs/namespace.c:3875
x64_sys_call+0x25c9/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:166
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: 0x03 -> 0x09

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10686 Comm: syz-executor.3 Not tainted 6.10.0-rc1-syzkaller-00304-g83814698cf48 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================


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