Hello, The following program triggers BUG in munlock_vma_pages_range: // autogenerated by syzkaller (http://github.com/google/syzkaller) #include <sys/mman.h> int main() { mmap((void*)0x20105000ul, 0xc00000ul, 0x2ul, 0x2172ul, -1, 0); mremap((void*)0x201fd000ul, 0x4000ul, 0xc00000ul, 0x3ul, 0x203f0000ul); return 0; } page:ffffea0001847cc0 count:0 mapcount:1 mapping:dead000000000400 index:0x20400 compound_mapcount: 1 flags: 0x5fffc0000000000() page dumped because: VM_BUG_ON_PAGE(PageMlocked(page)) ------------[ cut here ]------------ kernel BUG at mm/mlock.c:460! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN Modules linked in: CPU: 2 PID: 6526 Comm: a.out Not tainted 4.9.0-rc5+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8800681ca0c0 task.stack: ffff8800637f0000 RIP: 0010:[<ffffffff81965272>] [<ffffffff81965272>] munlock_vma_pages_range+0xcc2/0x1010 mm/mlock.c:460 RSP: 0018:ffff8800637f7178 EFLAGS: 00010292 RAX: 0000000000000000 RBX: ffffea0001847cc0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88006d016e08 RDI: ffffed000c6fee20 RBP: ffff8800637f7638 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: 0000000000000001 R12: ffffea0001847ce0 R13: ffffea0001840000 R14: dffffc0000000000 R15: ffff8800637f7610 FS: 0000000000000000(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004b2080 CR3: 0000000064f87000 CR4: 00000000000006e0 Stack: 0000000041b58ab3 ffffffff894cfa90 ffff8800637f74f0 ffff8800637f7578 0000000000000005 ffff88007fff8000 1ffff1000c6fee42 ffff8800637f74b0 0000000020400000 000000050c6fee41 ffffea000196c55c ffffed000c6feeaf Call Trace: [< inline >] munlock_vma_pages_all mm/internal.h:277 [<ffffffff8197261b>] exit_mmap+0x1bb/0x4e0 mm/mmap.c:2924 [< inline >] __mmput kernel/fork.c:866 [<ffffffff813f24ce>] mmput+0x20e/0x4c0 kernel/fork.c:888 [< inline >] exit_mm kernel/exit.c:512 [<ffffffff814119a0>] do_exit+0x960/0x2640 kernel/exit.c:815 [<ffffffff8141383e>] do_group_exit+0x14e/0x420 kernel/exit.c:931 [< inline >] SYSC_exit_group kernel/exit.c:942 [<ffffffff81413b32>] SyS_exit_group+0x22/0x30 kernel/exit.c:940 [<ffffffff88143885>] entry_SYSCALL_64_fastpath+0x23/0xc6 arch/x86/entry/entry_64.S:209 Code: 0b e8 53 2e d8 ff 48 c7 c6 c0 32 31 88 48 89 df e8 54 2e fd ff 0f 0b e8 3d 2e d8 ff 48 c7 c6 80 35 31 88 48 89 df e8 3e 2e fd ff <0f> 0b 48 89 85 a8 fb ff ff e8 20 2e d8 ff 48 8b 85 a8 fb ff ff RIP [<ffffffff81965272>] munlock_vma_pages_range+0xcc2/0x1010 mm/mlock.c:460 RSP <ffff8800637f7178> ---[ end trace 694dc6462f524cf9 ]--- Fixing recursive fault but reboot is needed! On commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (Nov 13). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>