bisecting fixing commit since 893af1c79e42e53af0da22165b46eea135af0613 building syzkaller on acb51638141ff960f547431757130749bc176bc0 testing commit 893af1c79e42e53af0da22165b46eea135af0613 with gcc (GCC) 8.4.1 20210217 kernel signature: 0e46310a55b5e8e87b78fd60dabe9cb5de0f12946a93765b3633995b1aea4ef6 all runs: crashed: WARNING in untrack_pfn testing current HEAD 2d19be4653f5e74ed95560b69f94eb6791d49af3 testing commit 2d19be4653f5e74ed95560b69f94eb6791d49af3 with gcc (GCC) 8.4.1 20210217 kernel signature: f8dc1014604717d22203fe49bdbb81e8174e233bb2c89bf10e6b3bb656232a86 run #0: crashed: WARNING in untrack_pfn run #1: crashed: WARNING in untrack_pfn run #2: crashed: WARNING in untrack_pfn run #3: crashed: WARNING in untrack_pfn run #4: crashed: WARNING in untrack_pfn run #5: crashed: WARNING in untrack_pfn run #6: crashed: WARNING in untrack_pfn run #7: crashed: WARNING in untrack_pfn run #8: crashed: WARNING in untrack_pfn run #9: OK revisions tested: 2, total time: 37m27.095979215s (build: 14m54.541193791s, test: 21m21.717901266s) the crash still happens on HEAD commit msg: Linux 4.19.177 crash: WARNING in untrack_pfn RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441409 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffeb81f2350 R08: 0000000000000000 R09: 00007ffeb81f2360 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007ffeb81f2370 R14: 00007ffeb81f23b0 R15: 000000000000006b WARNING: CPU: 0 PID: 12631 at arch/x86/mm/pat.c:1064 untrack_pfn+0x1cb/0x240 arch/x86/mm/pat.c:1073 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 12631 Comm: syz-executor164 Not tainted 4.19.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x171 lib/dump_stack.c:118 panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.8+0x1b/0x36 kernel/panic.c:541 report_bug+0x1a1/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:untrack_pfn+0x1cb/0x240 arch/x86/mm/pat.c:1064 Code: 00 00 00 48 c7 43 08 00 00 00 00 48 8b 45 d8 65 48 33 04 25 28 00 00 00 75 14 48 81 c4 b0 00 00 00 5b 41 5c 41 5d 41 5e 5d c3 <0f> 0b eb c1 e8 8c 83 0d 00 48 89 95 30 ff ff ff 48 89 b5 38 ff ff RSP: 0018:ffff8881da2778c0 EFLAGS: 00010282 RAX: 00000000ffffffea RBX: 1ffff1103b44ef1a RCX: 0000000000000000 RDX: 0000000000000004 RSI: 0000000000000004 RDI: ffffffff89c8b6e0 RBP: ffff8881da277990 R08: ffffed103bab4356 R09: ffffed103bab4355 R10: ffffed103bab4355 R11: ffff8881dd5a1aab R12: ffff8881dba1f840 R13: 0000000000000000 R14: ffff8881da277970 R15: ffff8881da277a60 unmap_single_vma+0x144/0x300 mm/memory.c:1547 unmap_vmas+0xe7/0x1a0 mm/memory.c:1598 exit_mmap+0x251/0x470 mm/mmap.c:3093 __mmput kernel/fork.c:1015 [inline] mmput+0x107/0x3f0 kernel/fork.c:1036 dup_mm kernel/fork.c:1300 [inline] copy_mm kernel/fork.c:1340 [inline] copy_process.part.34+0x2c90/0x76d0 kernel/fork.c:1912 copy_process kernel/fork.c:1718 [inline] _do_fork+0x16a/0xcb0 kernel/fork.c:2218 __do_sys_clone kernel/fork.c:2325 [inline] __se_sys_clone kernel/fork.c:2319 [inline] __x64_sys_clone+0xba/0x140 kernel/fork.c:2319 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441409 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffeb81f2328 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441409 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffeb81f2350 R08: 0000000000000000 R09: 00007ffeb81f2360 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007ffeb81f2370 R14: 00007ffeb81f23b0 R15: 000000000000006b Kernel Offset: disabled Rebooting in 86400 seconds..