bisecting fixing commit since daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b building syzkaller on eff43e99da12c6de1965548a619c3013b8ee791e testing commit daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b with gcc (GCC) 8.4.1 20210217 kernel signature: d26d2454b6828dba6099c4f554f19db64684e634fae11bac668e32d5fe6c56f9 run #0: crashed: general protection fault in mount_fs run #1: crashed: general protection fault in corrupted run #2: crashed: general protection fault in mount_fs run #3: crashed: general protection fault in mount_fs run #4: crashed: general protection fault in mount_fs run #5: crashed: general protection fault in mount_fs run #6: crashed: general protection fault in mount_fs run #7: crashed: general protection fault in corrupted run #8: crashed: general protection fault in mount_fs run #9: crashed: general protection fault in corrupted run #10: crashed: general protection fault in corrupted run #11: crashed: general protection fault in mount_fs run #12: crashed: general protection fault in mount_fs run #13: crashed: general protection fault in mount_fs run #14: crashed: general protection fault in mount_fs run #15: crashed: general protection fault in mount_fs run #16: crashed: general protection fault in mount_fs run #17: crashed: general protection fault in mount_fs run #18: crashed: general protection fault in mount_fs run #19: crashed: general protection fault in mount_fs testing current HEAD 97a8651cadce7c2b7c4d8f108b392eff31fe2c08 testing commit 97a8651cadce7c2b7c4d8f108b392eff31fe2c08 with gcc (GCC) 8.4.1 20210217 kernel signature: 995f475b68b8579d93ffb318058902097e7faa8e527f2f47855ea7189b29da5c run #0: crashed: general protection fault in mount_fs run #1: crashed: general protection fault in corrupted run #2: crashed: general protection fault in mount_fs run #3: crashed: general protection fault in mount_fs run #4: crashed: general protection fault in mount_fs run #5: crashed: general protection fault in mount_fs run #6: crashed: general protection fault in mount_fs run #7: crashed: general protection fault in corrupted run #8: crashed: general protection fault in mount_fs run #9: crashed: general protection fault in mount_fs revisions tested: 2, total time: 22m31.553768522s (build: 14m57.820437304s, test: 7m5.155163041s) the crash still happens on HEAD commit msg: Linux 4.19.189 crash: general protection fault in mount_fs R13: 0000000020000100 R14: 00007fbb54770000 R15: 0000000020000040 kasan: CONFIG_KASAN_INLINE enabled EXT4-fs (loop4): failed to initialize system zone (-12) kasan: GPF could be caused by NULL-ptr deref or user memory access EXT4-fs (loop4): mount failed general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 10442 Comm: syz-executor.3 Not tainted 4.19.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mount_fs+0xa9/0x2b0 fs/super.c:1266 Code: 4d 89 f0 48 3d 00 f0 ff ff 49 89 c5 0f 87 38 01 00 00 48 8d b8 c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b5 01 00 00 49 8b 9d c8 00 00 00 48 85 db 0f 84 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 RSP: 0018:ffff8880903b7cb0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880a3f7a800 RCX: 1ffff11012cca54d RDX: 0000000000000019 RSI: ffff888096652a48 RDI: 00000000000000c8 RBP: ffff8880903b7cf0 R08: ffff8880b5235000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89a98080 R13: 0000000000000000 R14: ffff8880b5235000 R15: 0000000000000000 FS: 00007f57ba8c5700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f464bd8d000 CR3: 000000009fbec000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 CPU: 0 PID: 10460 Comm: syz-executor.2 Not tainted 4.19.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ksys_mount+0xb1/0xd0 fs/namespace.c:3015 Call Trace: __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.2+0x5/0xa lib/fault-inject.c:149 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466daa Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f57ba8c4fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 __should_failslab+0xba/0xf0 mm/failslab.c:32 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa should_failslab+0x9/0x20 mm/slab_common.c:1588 RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007f57ba8c5000 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x28e/0x390 mm/slab.c:3557 RBP: 00007f57ba8c5040 R08: 00007f57ba8c5040 R09: 0000000020000080 kmem_cache_zalloc include/linux/slab.h:699 [inline] __kernfs_new_node+0xe7/0x6f0 fs/kernfs/dir.c:633 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 0000000020000100 R14: 00007f57ba8c5000 R15: 0000000020000040 Modules linked in: kernfs_new_node+0x62/0x110 fs/kernfs/dir.c:693 __kernfs_create_file+0x35/0x2e0 fs/kernfs/file.c:992 sysfs_add_file_mode_ns+0x1b0/0x4e0 fs/sysfs/file.c:307 sysfs_create_file_ns+0x12a/0x1c0 fs/sysfs/file.c:332 sysfs_create_file include/linux/sysfs.h:529 [inline] populate_dir lib/kobject.c:75 [inline] create_dir lib/kobject.c:92 [inline] kobject_add_internal+0x454/0x8d0 lib/kobject.c:247 kobject_add_varg lib/kobject.c:382 [inline] kobject_init_and_add+0xcf/0x120 lib/kobject.c:453 ext4_register_sysfs+0xbd/0x250 fs/ext4/sysfs.c:379 ext4_fill_super+0x6e1d/0xb670 fs/ext4/super.c:4530 mount_bdev+0x26f/0x330 fs/super.c:1158 ext4_mount+0x10/0x20 fs/ext4/super.c:6047 mount_fs+0x7f/0x2b0 fs/super.c:1261 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 ksys_mount+0xb1/0xd0 fs/namespace.c:3015 __do_sys_mount fs/namespace.c:3029 [inline] __se_sys_mount fs/namespace.c:3026 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3026 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466daa Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4875e13fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007f4875e14000 RBP: 00007f4875e14040 R08: 00007f4875e14040 R09: 0000000020000080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 0000000020000100 R14: 00007f4875e14000 R15: 0000000020000040 ---[ end trace 14d6c122c27742c2 ]--- RIP: 0010:mount_fs+0xa9/0x2b0 fs/super.c:1266 Code: 4d 89 f0 48 3d 00 f0 ff ff 49 89 c5 0f 87 38 01 00 00 48 8d b8 c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b5 01 00 00 49 8b 9d c8 00 00 00 48 85 db 0f 84 kobject_add_internal failed for loop2 (error: -12 parent: ext4) RSP: 0018:ffff8880903b7cb0 EFLAGS: 00010202 EXT4-fs (loop2): mount failed RAX: dffffc0000000000 RBX: ffff8880a3f7a800 RCX: 1ffff11012cca54d RDX: 0000000000000019 RSI: ffff888096652a48 RDI: 00000000000000c8 RBP: ffff8880903b7cf0 R08: ffff8880b5235000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89a98080 R13: 0000000000000000 R14: ffff8880b5235000 R15: 0000000000000000 FS: 00007f57ba8c5700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002fc3888 CR3: 000000009fbec000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400