syzbot

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BUG: KCSAN: data-race in mlock_new_folio / need_mlock_drain

read-write to 0xffff888237d27210 of 1 bytes by task 8016 on cpu 1:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 mlock_new_folio+0x143/0x240 mm/mlock.c:280
 folio_add_lru_vma+0x5f/0x70 mm/swap.c:528
 do_anonymous_page mm/memory.c:5312 [inline]
 do_pte_missing mm/memory.c:4475 [inline]
 handle_pte_fault mm/memory.c:6316 [inline]
 __handle_mm_fault mm/memory.c:6454 [inline]
 handle_mm_fault+0x2c3f/0x3020 mm/memory.c:6623
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1023/0x1ea0 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x242/0x390 mm/gup.c:1963
 do_mlock+0x47c/0x520 mm/mlock.c:653
 __do_sys_mlock mm/mlock.c:661 [inline]
 __se_sys_mlock mm/mlock.c:659 [inline]
 __x64_sys_mlock+0x36/0x50 mm/mlock.c:659
 x64_sys_call+0x1ab3/0x3020 arch/x86/include/generated/asm/syscalls_64.h:150
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d27210 of 1 bytes by task 8005 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:786 [inline]
 __lru_add_drain_all+0x273/0x450 mm/swap.c:877
 lru_add_drain_all+0x10/0x20 mm/swap.c:893
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 bdev_disk_changed+0xeb/0xd40 block/partitions/core.c:658
 loop_reread_partitions drivers/block/loop.c:448 [inline]
 loop_set_status+0x5db/0x6a0 drivers/block/loop.c:1277
 loop_set_status64 drivers/block/loop.c:1373 [inline]
 lo_ioctl+0x671/0x13a0 drivers/block/loop.c:1559
 blkdev_ioctl+0x387/0x460 block/ioctl.c:804
 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+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x06 -> 0x0b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8005 Comm: syz.2.1151 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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 loop2: p1 < > p2 p4 < p5 >
loop2: partition table partially beyond EOD, truncated
loop2: p1 start 134217728 is beyond EOD, truncated
loop2: p2 size 591360 extends beyond EOD, 
truncated
loop2: p5 size 591360 extends beyond EOD, truncated