bisecting fixing commit since 45f092f9e9cb31486db546e39bfe7cc0b3f57099
building syzkaller on 78ded1969a3882c1a5dc9cf32ed2ffc23119a4ca
testing commit 45f092f9e9cb31486db546e39bfe7cc0b3f57099 with gcc (GCC) 8.1.0
kernel signature: 6b50fbf9dd3e0b2ce8ac1535607747ae16d96a0414a427f63df23198b76f096c
all runs: crashed: general protection fault in sysfs_do_create_link_sd
testing current HEAD b850307b279cbd12ab8c654d1a3dfe55319cc475
testing commit b850307b279cbd12ab8c654d1a3dfe55319cc475 with gcc (GCC) 8.1.0
kernel signature: d88069fbf34c21639353af759a9f68b144bf03973937e147f73bdb2ebba587f8
all runs: crashed: general protection fault in sysfs_do_create_link_sd
revisions tested: 2, total time: 25m4.252901604s (build: 17m10.441867555s, test: 6m58.827986833s)
the crash still happens on HEAD
commit msg: Linux 4.14.184
crash: general protection fault in sysfs_do_create_link_sd
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee2e17c6d4
R13: 00000000004c2fa7 R14: 00000000004d66e8 R15: 0000000000000004
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: 0 PID: 7592 Comm: syz-executor.5 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809938a600 task.stack: ffff88808db18000
RIP: 0010:sysfs_do_create_link_sd.isra.2+0x48/0xf0 fs/sysfs/symlink.c:35
RSP: 0018:ffff88808db1fab0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff86bbb020 RCX: ffff88809938ae88
RDX: 0000000000000008 RSI: ffff88809938aeb0 RDI: ffffffff87a62a24
RBP: ffff88808db1fad8 R08: ffff88809938aed0 R09: 00000000000017aa
R10: 0000000000000028 R11: ffff88809938a600 R12: ffff8880a4ca0c40
R13: 0000000000000040 R14: 0000000000000001 R15: ffff888097dc2d50
FS:  00007fee2e17c700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e08baa000 CR3: 00000000aa9bc000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 sysfs_create_link+0x43/0xb0 fs/sysfs/symlink.c:92
 device_add_disk+0x981/0xd50 block/genhd.c:688
 add_disk include/linux/genhd.h:396 [inline]
 loop_add+0x5e2/0x810 drivers/block/loop.c:1904
 loop_control_ioctl+0x19e/0x2b0 drivers/block/loop.c:2001
 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+0x46/0xbb
RIP: 0033:0x459879
RSP: 002b:00007fee2e17bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fee2e17bc90 RCX: 0000000000459879
RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee2e17c6d4
R13: 00000000004c2fa7 R14: 00000000004d66e8 R15: 0000000000000004
Code: 00 00 49 89 f5 49 89 fc 48 c7 c7 20 2a a6 87 48 89 d3 41 89 ce e8 39 83 7c 04 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 86 00 00 00 4d 8b 6d 00 4d 85 ed 74 52 4c 89 
RIP: sysfs_do_create_link_sd.isra.2+0x48/0xf0 fs/sysfs/symlink.c:35 RSP: ffff88808db1fab0
---[ end trace eb65e0c99f23f9a7 ]---