bisecting fixing commit since 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 building syzkaller on 4afdfa205b55633e7eb9db03a9d099d7aa324801 testing commit 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 with gcc (GCC) 8.4.1 20210217 kernel signature: 485664a4d9eb362ea82eb4fc1d82a4a2caba3fce5a123a19a5e2043caf7a6bfd all runs: crashed: kernel BUG in __handle_mm_fault testing current HEAD 2d19be4653f5e74ed95560b69f94eb6791d49af3 testing commit 2d19be4653f5e74ed95560b69f94eb6791d49af3 with gcc (GCC) 8.4.1 20210217 kernel signature: 2f0271d5c4ed006d5c3592a6e42e43828bb8927bffd6618bacee2a811e5b1a8b all runs: crashed: kernel BUG in __handle_mm_fault revisions tested: 2, total time: 23m44.801795324s (build: 16m11.873402671s, test: 6m21.457511664s) the crash still happens on HEAD commit msg: Linux 4.19.177 crash: kernel BUG in __handle_mm_fault next ffff8881e7882ca0 prev ffff8881e7882da8 mm ffff8881d60a2940 prot 25 anon_vma 0000000000000000 vm_ops ffffffff87310ce0 pgoff 0 file ffff8881d74b3a80 private_data 0000000000000000 flags: 0xfe(write|exec|shared|mayread|maywrite|mayexec|mayshare) ------------[ cut here ]------------ kernel BUG at mm/memory.c:4040! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 7258 Comm: syz-executor.4 Not tainted 4.19.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:wp_huge_pmd mm/memory.c:4040 [inline] RIP: 0010:__handle_mm_fault+0x2192/0x4100 mm/memory.c:4248 Code: 00 00 00 4c 89 f7 e8 bd ec 09 00 f0 41 ff 0e 0f 85 54 ec ff ff 48 89 df e8 0b ed f5 ff e9 47 ec ff ff 48 89 df e8 e3 98 39 05 <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 ac d5 0b 00 41 89 c7 e9 RSP: 0018:ffff8881cd9e7cc8 EFLAGS: 00010296 RAX: 0000000000000137 RBX: ffff8881d71ac040 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87678680 RDI: ffffffff8a193aa0 RBP: ffff8881cd9e7de8 R08: ffffed103ed05081 R09: ffffed103ed05080 R10: ffffed103ed05080 R11: ffff8881f6828407 R12: ffff8881cd9e7dc0 R13: 1ffff11039b3cfa0 R14: ffffffff87310ce0 R15: 0000000000000080 FS: 0000000001a1e400(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8ffcb46000 CR3: 00000001d9153005 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: handle_mm_fault+0x3dd/0x8b0 mm/memory.c:4295 __do_page_fault+0x50e/0xb30 arch/x86/mm/fault.c:1412 do_page_fault+0x64/0x3b0 arch/x86/mm/fault.c:1487 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1205 RIP: 0033:0x45fb08 Code: d1 f3 a4 c3 80 fa 10 73 17 80 fa 08 73 27 80 fa 04 73 33 80 fa 01 77 3b 72 05 0f b6 0e 88 0f c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 fa 7f 07 c5 fa 7f 4c 17 f0 c3 48 8b 4c 16 f8 48 8b 36 48 89 4c RSP: 002b:00007ffe423bb738 EFLAGS: 00010206 RAX: 00000000200001c0 RBX: 000000000055c900 RCX: 0000000000960000 RDX: 0000000000000013 RSI: 0000000000560398 RDI: 00000000200001c0 RBP: 00007ffe423bb7d8 R08: 0000000000560278 R09: 0000000000000000 R10: 00007ffe423bb7f0 R11: 0000000000000246 R12: 00000000000003e8 R13: 000000000055bfac R14: 000000000055bf00 R15: 000000000055bfa0 Modules linked in: ---[ end trace b117b22bec2df70e ]--- RIP: 0010:wp_huge_pmd mm/memory.c:4040 [inline] RIP: 0010:__handle_mm_fault+0x2192/0x4100 mm/memory.c:4248 Code: 00 00 00 4c 89 f7 e8 bd ec 09 00 f0 41 ff 0e 0f 85 54 ec ff ff 48 89 df e8 0b ed f5 ff e9 47 ec ff ff 48 89 df e8 e3 98 39 05 <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 ac d5 0b 00 41 89 c7 e9 RSP: 0018:ffff8881cd9e7cc8 EFLAGS: 00010296 RAX: 0000000000000137 RBX: ffff8881d71ac040 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87678680 RDI: ffffffff8a193aa0 RBP: ffff8881cd9e7de8 R08: ffffed103ed05081 R09: ffffed103ed05080 R10: ffffed103ed05080 R11: ffff8881f6828407 R12: ffff8881cd9e7dc0 R13: 1ffff11039b3cfa0 R14: ffffffff87310ce0 R15: 0000000000000080 FS: 0000000001a1e400(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055eaa6fa0c00 CR3: 00000001d9153005 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400