syzbot

bond1: entered promiscuous mode
bond1: entered allmulticast mode
8021q: adding VLAN 0 to HW filter on device bond1
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BUG: KCSAN: data-race in shmem_fallocate / shmem_fault

write to 0xffff8881046c9448 of 8 bytes by task 12343 on cpu 1:
 shmem_fallocate+0x221/0x840 mm/shmem.c:3681
 vfs_fallocate+0x410/0x450 fs/open.c:341
 madvise_remove mm/madvise.c:1043 [inline]
 madvise_vma_behavior mm/madvise.c:1274 [inline]
 madvise_walk_vmas mm/madvise.c:1541 [inline]
 madvise_do_behavior+0x1152/0x1f20 mm/madvise.c:1733
 do_madvise+0x103/0x190 mm/madvise.c:1826
 __do_sys_madvise mm/madvise.c:1835 [inline]
 __se_sys_madvise mm/madvise.c:1833 [inline]
 __x64_sys_madvise+0x64/0x80 mm/madvise.c:1833
 x64_sys_call+0x2455/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:29
 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 0xffff8881046c9448 of 8 bytes by task 12338 on cpu 0:
 shmem_fault+0x90/0x250 mm/shmem.c:2730
 __do_fault+0xb9/0x200 mm/memory.c:5169
 do_read_fault mm/memory.c:5590 [inline]
 do_fault mm/memory.c:5724 [inline]
 do_pte_missing mm/memory.c:4251 [inline]
 handle_pte_fault mm/memory.c:6069 [inline]
 __handle_mm_fault mm/memory.c:6212 [inline]
 handle_mm_fault+0xf78/0x2be0 mm/memory.c:6381
 faultin_page mm/gup.c:1186 [inline]
 __get_user_pages+0x1036/0x1fb0 mm/gup.c:1488
 populate_vma_page_range mm/gup.c:1926 [inline]
 __mm_populate+0x243/0x3a0 mm/gup.c:2029
 mm_populate include/linux/mm.h:3348 [inline]
 vm_mmap_pgoff+0x232/0x2e0 mm/util.c:584
 ksys_mmap_pgoff+0xc2/0x310 mm/mmap.c:607
 x64_sys_call+0x1602/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:10
 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: 0x0000000000000000 -> 0xffffc90003097be8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 12338 Comm: syz.3.11887 Not tainted 6.16.0-rc3-syzkaller-00057-g92ca6c498a5e #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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