BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 7bb17067 P4D 7bb17067 PUD 695ce067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4433 Comm: syz-executor.2 Not tainted 5.18.0-rc5-syzkaller-00120-gedae34a3ed92 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000007a60 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88807a0b8990 RCX: 0000000000000100 RDX: 1ffff1100f417133 RSI: ffff8880782e7140 RDI: ffff88807302bc00 RBP: ffff88807302bc00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d5c227 R11: 0000000000000000 R12: ffff8880782e7140 R13: 0000000000000000 R14: ffff88807302c360 R15: ffff88807928812c FS: 00007f26c6e71700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000001a2ff000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __tcp_transmit_skb+0x1098/0x38b0 net/ipv4/tcp_output.c:1372 tcp_transmit_skb net/ipv4/tcp_output.c:1421 [inline] tcp_xmit_probe_skb+0x28c/0x320 net/ipv4/tcp_output.c:4010 tcp_write_wakeup+0x1bd/0x610 net/ipv4/tcp_output.c:4063 tcp_send_probe0+0x44/0x560 net/ipv4/tcp_output.c:4078 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x9ed/0xbc0 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:refill_obj_stock+0x34a/0x810 mm/memcontrol.c:3207 Code: 55 be cb 81 4c 89 ef e8 b4 ed 91 ff 4d 85 f6 0f 85 b7 01 00 00 9c 58 f6 c4 02 0f 85 f0 02 00 00 4d 85 f6 74 01 fb 48 8b 04 24 <48> 85 c0 74 08 48 89 c7 e8 e9 74 ff ff 45 85 ff 0f 85 99 00 00 00 RSP: 0018:ffffc9000c0a7708 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff8880b9c35f20 RCX: 1ffffffff201558e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880b9c35f48 R08: 0000000000000001 R09: ffffffff9006d9a7 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801b52d080 R13: ffff8880b9c35f20 R14: 0000000000000200 R15: 0000000000000000 obj_cgroup_charge+0x3d7/0x700 mm/memcontrol.c:3253 memcg_slab_pre_alloc_hook mm/slab.h:504 [inline] slab_pre_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3131 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x92/0x3b0 mm/slub.c:3242 kmem_cache_zalloc include/linux/slab.h:704 [inline] alloc_buffer_head+0x20/0x140 fs/buffer.c:3300 alloc_page_buffers+0x285/0x7a0 fs/buffer.c:829 create_empty_buffers+0x2c/0x1060 fs/buffer.c:1558 ext4_block_write_begin+0x117a/0x16e0 fs/ext4/inode.c:1060 ext4_da_write_begin+0x3e9/0xb40 fs/ext4/inode.c:2975 generic_perform_write+0x249/0x560 mm/filemap.c:3787 ext4_buffered_write_iter+0x15b/0x330 fs/ext4/file.c:270 ext4_file_write_iter+0x43c/0x1510 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2050 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 ksys_write+0x127/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f26c5c890e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f26c6e71168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f26c5d9bf60 RCX: 00007f26c5c890e9 RDX: 00000000ffffff6a RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007f26c5ce308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd825b03bf R14: 00007f26c6e71300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90000007a60 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88807a0b8990 RCX: 0000000000000100 RDX: 1ffff1100f417133 RSI: ffff8880782e7140 RDI: ffff88807302bc00 RBP: ffff88807302bc00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87d5c227 R11: 0000000000000000 R12: ffff8880782e7140 R13: 0000000000000000 R14: ffff88807302c360 R15: ffff88807928812c FS: 00007f26c6e71700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000001a2ff000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 55 push %rbp 1: be cb 81 4c 89 mov $0x894c81cb,%esi 6: ef out %eax,(%dx) 7: e8 b4 ed 91 ff callq 0xff91edc0 c: 4d 85 f6 test %r14,%r14 f: 0f 85 b7 01 00 00 jne 0x1cc 15: 9c pushfq 16: 58 pop %rax 17: f6 c4 02 test $0x2,%ah 1a: 0f 85 f0 02 00 00 jne 0x310 20: 4d 85 f6 test %r14,%r14 23: 74 01 je 0x26 25: fb sti 26: 48 8b 04 24 mov (%rsp),%rax * 2a: 48 85 c0 test %rax,%rax <-- trapping instruction 2d: 74 08 je 0x37 2f: 48 89 c7 mov %rax,%rdi 32: e8 e9 74 ff ff callq 0xffff7520 37: 45 85 ff test %r15d,%r15d 3a: 0f 85 99 00 00 00 jne 0xd9