bisecting fixing commit since 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 building syzkaller on 4afdfa205b55633e7eb9db03a9d099d7aa324801 testing commit 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 with gcc (GCC) 8.4.1 20210217 kernel signature: 25bead0510d7754c83744b211f0f994371f169917d18d752d1fe457e56beae08 run #0: crashed: kernel BUG in __handle_mm_fault run #1: crashed: kernel BUG in __handle_mm_fault run #2: crashed: kernel BUG in corrupted run #3: crashed: kernel BUG in __handle_mm_fault run #4: crashed: kernel BUG in __handle_mm_fault run #5: crashed: kernel BUG in __handle_mm_fault run #6: crashed: kernel BUG in __handle_mm_fault run #7: crashed: kernel BUG in __handle_mm_fault run #8: crashed: kernel BUG in __handle_mm_fault run #9: crashed: kernel BUG in __handle_mm_fault run #10: crashed: kernel BUG in __handle_mm_fault run #11: crashed: kernel BUG in __handle_mm_fault run #12: crashed: kernel BUG in __handle_mm_fault run #13: crashed: kernel BUG in __handle_mm_fault run #14: crashed: kernel BUG in __handle_mm_fault run #15: crashed: kernel BUG in __handle_mm_fault run #16: crashed: kernel BUG in __handle_mm_fault run #17: crashed: kernel BUG in __handle_mm_fault run #18: crashed: kernel BUG in __handle_mm_fault run #19: crashed: kernel BUG in __handle_mm_fault testing current HEAD 6b7b0056defc6eb5c87bbe4690ccda547b2891aa testing commit 6b7b0056defc6eb5c87bbe4690ccda547b2891aa with gcc (GCC) 8.4.1 20210217 kernel signature: 27e54d010edf91658afbf866196eaf20f91ec69d93da3161534d9a7aa3797be5 run #0: crashed: kernel BUG in __handle_mm_fault run #1: crashed: kernel BUG in corrupted run #2: crashed: kernel BUG in __handle_mm_fault run #3: crashed: kernel BUG in __handle_mm_fault run #4: crashed: kernel BUG in __handle_mm_fault run #5: crashed: kernel BUG in __handle_mm_fault run #6: crashed: kernel BUG in __handle_mm_fault run #7: crashed: kernel BUG in __handle_mm_fault run #8: crashed: kernel BUG in __handle_mm_fault run #9: crashed: kernel BUG in __handle_mm_fault revisions tested: 2, total time: 29m34.028124447s (build: 22m3.441718979s, test: 6m47.705512293s) the crash still happens on HEAD commit msg: Linux 4.19.192 crash: kernel BUG in __handle_mm_fault next ffff8881d3eb9b98 prev ffff8881d3eb9ca0 mm ffff8881d9cd6300 prot 25 anon_vma 0000000000000000 vm_ops ffffffff87311020 pgoff 0 file ffff8881db4a22c0 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: 0 PID: 7187 Comm: syz-executor.1 Not tainted 4.19.192-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 1d f0 09 00 f0 41 ff 0e 0f 85 54 ec ff ff 48 89 df e8 cb e8 f5 ff e9 47 ec ff ff 48 89 df e8 55 02 3b 05 <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 0c d9 0b 00 41 89 c7 e9 RSP: 0018:ffff8881d9427cc8 EFLAGS: 00010296 RAX: 0000000000000137 RBX: ffff8881e2d5c040 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87679fc0 RDI: ffffffff8a193aa0 RBP: ffff8881d9427de8 R08: ffffed103ed05081 R09: ffffed103ed05080 R10: ffffed103ed05080 R11: ffff8881f6828407 R12: ffff8881d9427dc0 R13: 1ffff1103b284fa0 R14: ffffffff87311020 R15: 0000000000000080 FS: 0000000002527400(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcdc9251000 CR3: 00000001d0c21003 CR4: 00000000001606f0 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:00007ffc69b288c8 EFLAGS: 00010206 RAX: 00000000200001c0 RBX: 000000000055c900 RCX: 0000000000960000 RDX: 0000000000000013 RSI: 0000000000560398 RDI: 00000000200001c0 RBP: 00007ffc69b28968 R08: 0000000000560278 R09: 0000000000000000 R10: 00007ffc69b28980 R11: 0000000000000246 R12: 00000000000003e8 R13: 000000000055c04c R14: 000000000055bf00 R15: 000000000055c040 Modules linked in: ---[ end trace b25ca1ac2f9777c8 ]--- 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 1d f0 09 00 f0 41 ff 0e 0f 85 54 ec ff ff 48 89 df e8 cb e8 f5 ff e9 47 ec ff ff 48 89 df e8 55 02 3b 05 <0f> 0b 49 8d 84 24 60 ff ff ff 48 89 c7 e8 0c d9 0b 00 41 89 c7 e9 RSP: 0018:ffff8881d9427cc8 EFLAGS: 00010296 RAX: 0000000000000137 RBX: ffff8881e2d5c040 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87679fc0 RDI: ffffffff8a193aa0 RBP: ffff8881d9427de8 R08: ffffed103ed05081 R09: ffffed103ed05080 R10: ffffed103ed05080 R11: ffff8881f6828407 R12: ffff8881d9427dc0 R13: 1ffff1103b284fa0 R14: ffffffff87311020 R15: 0000000000000080 FS: 0000000002527400(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000026a6768 CR3: 00000001d0c21006 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400