bisecting fixing commit since 45f092f9e9cb31486db546e39bfe7cc0b3f57099
building syzkaller on 6b8391d069ed24abb321ad3e7564292a6d42a997
testing commit 45f092f9e9cb31486db546e39bfe7cc0b3f57099 with gcc (GCC) 8.1.0
kernel signature: 9e31b6b5346bdbaf2db244e4ddc4d94c0b1223c595ee41c761f216232c929228
all runs: crashed: general protection fault in kobject_uevent
testing current HEAD 9fa690a2a016e1b55356835f047b952e67d3d73a
testing commit 9fa690a2a016e1b55356835f047b952e67d3d73a with gcc (GCC) 8.1.0
kernel signature: b7ca506eb9d95afb4b483827454591676d2bfb6faa2a89a5f0b1ca8e72aea732
all runs: crashed: general protection fault in kobject_uevent
revisions tested: 2, total time: 31m39.593266022s (build: 16m27.209549435s, test: 14m29.445143821s)
the crash still happens on HEAD
commit msg: Linux 4.14.169
crash: general protection fault in kobject_uevent
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 6878 Comm: syz-executor.0 Not tainted 4.14.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a8812240 task.stack: ffff888087da0000
RIP: 0010:kobject_uevent_env+0x93/0xb60 lib/kobject_uevent.c:355
RSP: 0018:ffff888087da7a88 EFLAGS: 00010206
RAX: 0000000000000018 RBX: 00000000000000a0 RCX: 1ffff11015102556
RDX: 1ffffffff0e4c932 RSI: 0000000000000002 RDI: 00000000000000c0
RBP: ffff888087da7b18 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000028 R11: ffff8880a8812240 R12: ffff88808dc55540
R13: dffffc0000000000 R14: 00000000000000a0 R15: ffff88808d40b9a8
FS:  0000000001e74940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000758080 CR3: 000000008b560000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kobject_uevent+0xb/0x10 lib/kobject_uevent.c:553
 loop_clr_fd+0x492/0xac0 drivers/block/loop.c:1069
 lo_ioctl+0x7e3/0x1c70 drivers/block/loop.c:1424
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x784/0x16b0 block/ioctl.c:594
 block_ioctl+0xd7/0x130 fs/block_dev.c:1881
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x74/0x80 fs/ioctl.c:692
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459697
RSP: 002b:00007ffd6a08ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459697
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
RBP: 0000000000000a92 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6a08acb0 R14: 00000000000698f9 R15: 00007ffd6a08acc0
Code: 18 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 50 09 00 00 48 8b 5b 18 48 85 db 0f 84 d6 01 00 00 48 8d 7b 20 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 0f 85 23 09 00 00 4c 8b 63 20 4d 85 e4 74 be 4d 
RIP: kobject_uevent_env+0x93/0xb60 lib/kobject_uevent.c:355 RSP: ffff888087da7a88
---[ end trace 06b539d3bbf288f6 ]---