bisecting fixing commit since daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b building syzkaller on eff43e99da12c6de1965548a619c3013b8ee791e testing commit daefdc9eb24bfa11ab77a4b2a9c3923f1051fe0b with gcc (GCC) 8.4.1 20210217 kernel signature: f7286e0967c5750634fda4c19fd132f00fa51d2fa130c1f8017cb1f196745cc5 run #0: crashed: general protection fault in mount_fs run #1: crashed: general protection fault in mount_fs 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 corrupted run #7: crashed: general protection fault in mount_fs run #8: crashed: general protection fault in mount_fs run #9: crashed: general protection fault in mount_fs run #10: crashed: general protection fault in vfs_kern_mount 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 9f84340f012ee60c12aacc03662bcdd67419a31a testing commit 9f84340f012ee60c12aacc03662bcdd67419a31a with gcc (GCC) 8.4.1 20210217 kernel signature: 0c8436e3251589c93e07669f66c064c85a4b8b6f755fd9d79b6b6497aac3b05f all runs: crashed: general protection fault in mount_fs revisions tested: 2, total time: 23m19.773107808s (build: 16m10.862947534s, test: 6m38.300532227s) the crash still happens on HEAD commit msg: Linux 4.19.196 crash: general protection fault in mount_fs Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.2+0x5/0xa lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 should_failslab+0x9/0x20 mm/slab_common.c:1588 general protection fault: 0000 [#1] PREEMPT SMP KASAN 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 CPU: 1 PID: 10379 Comm: syz-executor.3 Not tainted 4.19.196-syzkaller #0 kmem_cache_zalloc include/linux/slab.h:699 [inline] ext4_mb_add_groupinfo+0x317/0xb60 fs/ext4/mballoc.c:2429 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ext4_mb_init_backend fs/ext4/mballoc.c:2517 [inline] ext4_mb_init+0xa7b/0x1550 fs/ext4/mballoc.c:2686 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 ext4_fill_super+0x6489/0xb610 fs/ext4/super.c:4481 RSP: 0018:ffff8880b054fcb0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880a9d19e00 RCX: 1ffff1101678118d RDX: 0000000000000019 RSI: ffff8880b3c08c48 RDI: 00000000000000c8 RBP: ffff8880b054fcf0 R08: ffff8880b3715000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89a98300 R13: 0000000000000000 R14: ffff8880b3715000 R15: 0000000000000000 FS: 00007fb3e939a700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 mount_bdev+0x26f/0x330 fs/super.c:1158 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056381924adb8 CR3: 0000000097755000 CR4: 00000000001406e0 ext4_mount+0x10/0x20 fs/ext4/super.c:6046 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 mount_fs+0x7f/0x2b0 fs/super.c:1261 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 vfs_kern_mount.part.11+0x58/0x3d0 fs/namespace.c:961 Call Trace: vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x376/0x2710 fs/namespace.c:2799 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 ksys_mount+0xb1/0xd0 fs/namespace.c:3015 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 __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 entry_SYSCALL_64_after_hwframe+0x49/0xbe do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 RIP: 0033:0x466daa entry_SYSCALL_64_after_hwframe+0x49/0xbe 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 RIP: 0033:0x466daa RSP: 002b:00007feab588afa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 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 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007feab588b000 RSP: 002b:00007fb3e9399fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RBP: 00007feab588b040 R08: 00007feab588b040 R09: 0000000020000080 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007fb3e939a000 R13: 0000000020000100 R14: 00007feab588b000 R15: 0000000020000040 RBP: 00007fb3e939a040 R08: 00007fb3e939a040 R09: 0000000020000080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 0000000020000100 R14: 00007fb3e939a000 R15: 0000000020000040 Modules linked in: EXT4-fs: failed to create workqueue EXT4-fs (loop0): mount failed CPU: 0 PID: 10385 Comm: syz-executor.1 Tainted: G D 4.19.196-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 ---[ end trace cdb5829bf1f0d4bf ]--- fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.2+0x5/0xa lib/fault-inject.c:149 __should_failslab+0xba/0xf0 mm/failslab.c:32 RIP: 0010:mount_fs+0xa9/0x2b0 fs/super.c:1266 should_failslab+0x9/0x20 mm/slab_common.c:1588 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc_node mm/slab.c:3304 [inline] kmem_cache_alloc_node_trace+0x256/0x3e0 mm/slab.c:3666 __do_kmalloc_node mm/slab.c:3688 [inline] __kmalloc_node+0x3c/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:557 [inline] kvmalloc_node+0x68/0x70 mm/util.c:423 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 kvmalloc include/linux/mm.h:577 [inline] kvzalloc include/linux/mm.h:585 [inline] ext4_alloc_flex_bg_array+0xf2/0x4c0 fs/ext4/super.c:2320 ext4_fill_flex_info fs/ext4/super.c:2368 [inline] ext4_fill_super+0x82aa/0xb610 fs/ext4/super.c:4516 mount_bdev+0x26f/0x330 fs/super.c:1158 RSP: 0018:ffff8880b054fcb0 EFLAGS: 00010202 ext4_mount+0x10/0x20 fs/ext4/super.c:6046 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 RAX: dffffc0000000000 RBX: ffff8880a9d19e00 RCX: 1ffff1101678118d 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 RDX: 0000000000000019 RSI: ffff8880b3c08c48 RDI: 00000000000000c8 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:00007f349a37ffa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007f349a380000 RBP: ffff8880b054fcf0 R08: ffff8880b3715000 R09: 0000000000000000 RBP: 00007f349a380040 R08: 00007f349a380040 R09: 0000000020000080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 0000000020000100 R14: 00007f349a380000 R15: 0000000020000040 EXT4-fs (loop1): not enough memory for 1 flex group pointers EXT4-fs (loop4): failed to initialize mballoc (-12) EXT4-fs (loop1): unable to initialize flex_bg meta info! EXT4-fs (loop4): mount failed EXT4-fs (loop1): mount failed R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89a98300 EXT4-fs (loop2): can't allocate buddy mem R13: 0000000000000000 R14: ffff8880b3715000 R15: 0000000000000000 kasan: CONFIG_KASAN_INLINE enabled FS: 00007fb3e939a700(0000) GS:ffff8880ba300000(0000) knlGS:0000000000000000 kasan: GPF could be caused by NULL-ptr deref or user memory access CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 EXT4-fs (loop2): failed to initialize mballoc (-12) CR2: 000056381923e2c8 CR3: 0000000097755000 CR4: 00000000001406e0 general protection fault: 0000 [#2] PREEMPT SMP KASAN DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 CPU: 0 PID: 10385 Comm: syz-executor.1 Tainted: G D 4.19.196-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 EXT4-fs (loop5): can't allocate mem for a buddy group RSP: 0018:ffff8880aef37cb0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880977c9a00 RCX: ffff88809fbca0c0 RDX: 0000000000000019 RSI: ffffffff88502040 RDI: 00000000000000c8 RBP: ffff8880aef37cf0 R08: ffff8880b428f000 R09: 0000000021ee53d5 R10: 00000000a2d9cfc6 R11: 0000000000000000 R12: ffffffff89a98300 R13: 0000000000000000 R14: ffff8880b428f000 R15: 0000000000000000 FS: 00007f349a380700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f832d926000 CR3: 00000000983ee000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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 EXT4-fs (loop5): failed to initialize mballoc (-12) 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 EXT4-fs (loop5): mount failed 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:00007f349a37ffa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000466daa RDX: 0000000020000080 RSI: 0000000020000100 RDI: 00007f349a380000 RBP: 00007f349a380040 R08: 00007f349a380040 R09: 0000000020000080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000080 R13: 0000000020000100 R14: 00007f349a380000 R15: 0000000020000040 Modules linked in: EXT4-fs (loop2): mount failed