BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 9f56b067 P4D 9f56b067 PUD 8df4c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 18164 Comm: syz-executor.1 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202 Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2 RSP: 0018:ffffc9001675f800 EFLAGS: 00010246 RAX: ffffffff839f8336 RBX: 0000000000000000 RCX: ffff8880a79ae2c0 RDX: 0000000000000000 RSI: ffffffff8903523f RDI: ffffffff88e90cfe RBP: 0000000000001000 R08: ffffffff81cb531b R09: fffffbfff12d8975 R10: fffffbfff12d8975 R11: 0000000000000000 R12: 0000000000001000 R13: 0000000000034a38 R14: ffffffff8903523f R15: ffffffff88e90cfe FS: 00007fad8987f700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000009dda7000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled+0x16/0x240 lib/smp_processor_id.c:13 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:314 [inline] rcu_is_watching+0x1c/0xa0 kernel/rcu/tree.c:1079 rcu_read_lock_held_common kernel/rcu/update.c:118 [inline] rcu_read_lock_sched_held+0x11/0xa0 kernel/rcu/update.c:133 trace_block_touch_buffer+0x22b/0x2c0 include/trace/events/block.h:45 touch_buffer fs/buffer.c:62 [inline] __find_get_block+0x23c/0xaa0 fs/buffer.c:1333 sb_find_get_block include/linux/buffer_head.h:338 [inline] recently_deleted fs/ext4/ialloc.c:682 [inline] find_inode_bit+0x2fa/0x660 fs/ext4/ialloc.c:724 __ext4_new_inode+0x1003/0x5940 fs/ext4/ialloc.c:927 ext4_create+0x1eb/0x450 fs/ext4/namei.c:2614 lookup_open fs/namei.c:3081 [inline] open_last_lookups fs/namei.c:3155 [inline] path_openat+0x17ee/0x38b0 fs/namei.c:3343 do_filp_open+0x191/0x3a0 fs/namei.c:3373 do_sys_openat2+0x463/0x770 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] __do_sys_openat fs/open.c:1209 [inline] __se_sys_openat fs/open.c:1204 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1204 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fad8987ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7ca0 RCX: 000000000045ca59 RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007ab R14: 00000000004ca894 R15: 00007fad8987f6d4 Modules linked in: CR2: 0000000000000000 ---[ end trace f67d95f6c51a1ac2 ]--- RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202 Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2 RSP: 0018:ffffc9001675f800 EFLAGS: 00010246 RAX: ffffffff839f8336 RBX: 0000000000000000 RCX: ffff8880a79ae2c0 RDX: 0000000000000000 RSI: ffffffff8903523f RDI: ffffffff88e90cfe RBP: 0000000000001000 R08: ffffffff81cb531b R09: fffffbfff12d8975 R10: fffffbfff12d8975 R11: 0000000000000000 R12: 0000000000001000 R13: 0000000000034a38 R14: ffffffff8903523f R15: ffffffff88e90cfe FS: 00007fad8987f700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000009dda7000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400