bisecting fixing commit since 893af1c79e42e53af0da22165b46eea135af0613
building syzkaller on acb51638141ff960f547431757130749bc176bc0
testing commit 893af1c79e42e53af0da22165b46eea135af0613 with gcc (GCC) 8.1.0
kernel signature: 674076fff8700b9d33d26806ab224db08e82678e59fecf861304d2de29c26cdd
run #0: crashed: WARNING in corrupted
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in corrupted
run #3: crashed: WARNING in corrupted
run #4: crashed: WARNING in untrack_pfn
run #5: crashed: WARNING in untrack_pfn
run #6: crashed: WARNING in corrupted
run #7: crashed: WARNING in untrack_pfn
run #8: crashed: WARNING in corrupted
run #9: crashed: WARNING in corrupted
testing current HEAD 2263955bf7e71ca8419b64d7a60510aad29002f6
testing commit 2263955bf7e71ca8419b64d7a60510aad29002f6 with gcc (GCC) 8.1.0
kernel signature: 5e89d4862920e19bfa8d40d13ff6a7942a57f250ac784b34598455636868f3ca
all runs: crashed: WARNING in untrack_pfn
revisions tested: 2, total time: 23m42.862827348s (build: 17m8.961101375s, test: 5m48.12245474s)
the crash still happens on HEAD
commit msg: Linux 4.19.170
crash: WARNING in untrack_pfn
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f778b2436d4
R13: 00000000004bfd66 R14: 00000000004d1ab8 R15: 0000000000000004
WARNING: CPU: 0 PID: 6756 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: 6756 Comm: syz-executor.5 Not tainted 4.19.170-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+0x1a4/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [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 2c 84 0d 00 48 89 95 30 ff ff ff 48 89 b5 38 ff ff
RSP: 0018:ffff8881d87c78c0 EFLAGS: 00010282
RAX: 00000000ffffffea RBX: 1ffff1103b0f8f1a RCX: 0000000000000000
RDX: 0000000000000004 RSI: 0000000000000004 RDI: ffffffff89c8b6a0
RBP: ffff8881d87c7990 R08: ffffed103c7620bc R09: ffffed103c7620bb
R10: ffffed103c7620bb R11: ffff8881e3b105db R12: ffff8881e1b59ca0
R13: 0000000000000000 R14: ffff8881d87c7970 R15: ffff8881d87c7a60
 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:1304 [inline]
 copy_mm kernel/fork.c:1344 [inline]
 copy_process.part.34+0x2c97/0x7690 kernel/fork.c:1916
 copy_process kernel/fork.c:1722 [inline]
 _do_fork+0x16a/0xcb0 kernel/fork.c:2228
 __do_sys_clone kernel/fork.c:2335 [inline]
 __se_sys_clone kernel/fork.c:2329 [inline]
 __x64_sys_clone+0xba/0x140 kernel/fork.c:2329
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598a9
Code: 7d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 4b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f778b242c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f778b242c90 RCX: 00000000004598a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f778b2436d4
R13: 00000000004bfd66 R14: 00000000004d1ab8 R15: 0000000000000004
Kernel Offset: disabled
Rebooting in 86400 seconds..