bisecting fixing commit since 68d7a45eec101bc1550294c0e675a490c047b2e5
building syzkaller on 8e3c52b11d5d0843be47f41e00c5612ce29811b0
testing commit 68d7a45eec101bc1550294c0e675a490c047b2e5 with gcc (GCC) 8.1.0
kernel signature: 2008834330b9a78721998f2de13e43daa60c1a7a154ec3bb70c02fc62780fed6
all runs: crashed: WARNING in __vm_enough_memory
testing current HEAD 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796
testing commit 98db2bf27b9ed2d5ed0b6c9c8a4bfcb127a19796 with gcc (GCC) 8.1.0
kernel signature: 64d478a44b5e6038bd85d1a08f633068ee822e207334b9b94786357517204b55
all runs: crashed: WARNING in __vm_enough_memory
revisions tested: 2, total time: 23m59.459899846s (build: 16m56.823088533s, test: 6m22.594204676s)
the crash still happens on HEAD
commit msg: Linux 4.14.171
crash: WARNING in __vm_enough_memory
audit: type=1400 audit(1581831868.033:41): avc:  denied  { map } for  pid=6977 comm="syz-executor.2" path="/dev/ashmem" dev="devtmpfs" ino=15200 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1
memory commitment underflow
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6977 at mm/util.c:606 __vm_enough_memory.cold.5+0x13/0x62 mm/util.c:604
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6977 Comm: syz-executor.2 Not tainted 4.14.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x36a kernel/panic.c:183
 __warn.cold.8+0x25/0x2a kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:__vm_enough_memory.cold.5+0x13/0x62 mm/util.c:604
RSP: 0018:ffff888078c0fbb0 EFLAGS: 00010282
RAX: 000000000000001b RBX: ffffffff87a05c40 RCX: 0000000000000000
RDX: 000000000000001b RSI: ffff88808b3f0b80 RDI: ffffed100f181f6d
RBP: ffff888078c0fbe8 R08: ffff88808b3f0ba0 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000000 R12: 0000000000000021
R13: 0000000000000001 R14: ffff888072578080 R15: fff80000000126d1
 security_vm_enough_memory_mm+0x80/0xa0 security/security.c:328
 mmap_region+0x1d4/0xfa0 mm/mmap.c:1667
 do_mmap+0x544/0xe20 mm/mmap.c:1495
 do_mmap_pgoff include/linux/mm.h:2173 [inline]
 vm_mmap_pgoff+0x181/0x200 mm/util.c:333
 SYSC_mmap_pgoff mm/mmap.c:1545 [inline]
 SyS_mmap_pgoff+0x9d/0x6b0 mm/mmap.c:1503
 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0x1c9/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x458dea
RSP: 002b:00007ffe5c257838 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458dea
RDX: 0000000000000003 RSI: 0000000000021000 RDI: 0000000000000000
RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000020022 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000021000 R14: 0000000000020022 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..