bisecting fixing commit since db1892238c55c5138801f131a837ccd0056f002e
building syzkaller on f3f7d9c8c3dfa1406a5f5a5f5f45a351f533139f
testing commit db1892238c55c5138801f131a837ccd0056f002e with gcc (GCC) 8.1.0
kernel signature: 1708a4ddffa2c1ce1fecc3edbffe1de83ef0b5c99dbf0f738bebf8f10e230f3e
run #0: crashed: general protection fault in kobject_uevent
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD 050272a0423e68207fd2367831ae610680129062
testing commit 050272a0423e68207fd2367831ae610680129062 with gcc (GCC) 8.1.0
kernel signature: f1f1ec7209ea377c595a1e0286eb46a7a10a84502d2accd59eef430964f2e668
run #0: crashed: general protection fault in kobject_uevent
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
revisions tested: 2, total time: 40m13.824867451s (build: 17m23.411743835s, test: 21m36.656780201s)
the crash still happens on HEAD
commit msg: Linux 4.14.177
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: 6260 Comm: syz-executor.0 Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809760c2c0 task.stack: ffff88808de50000
RIP: 0010:kobject_uevent_env+0x93/0xb60 lib/kobject_uevent.c:355
RSP: 0018:ffff88808de57a88 EFLAGS: 00010206
RAX: 0000000000000018 RBX: 00000000000000a0 RCX: 1ffff11012ec1967
RDX: 1ffffffff0e4cb56 RSI: 0000000000000002 RDI: 00000000000000c0
RBP: ffff88808de57b18 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000028 R11: ffff88809760c2c0 R12: ffff888092708ac0
R13: dffffc0000000000 R14: 00000000000000a0 R15: ffff888088757528
FS:  00000000012be940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001cad978 CR3: 00000000903cf000 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: 0033:0x4598c7
RSP: 002b:00007ffcf3072b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004598c7
RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
RBP: 000000000000085f R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcf3072bc0 R14: 000000000004c028 R15: 00007ffcf3072bd0
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: ffff88808de57a88
---[ end trace 822a17e146706d01 ]---