Dear Linux Developer, Recently when using our tool to fuzz kernel, the following crash was triggered: HEAD commit: c5eb0a61238d Linux 5.18-rc6 git tree: upstream compiler: clang 12.0.0 console output: https://drive.google.com/file/d/1zbd9t-NNorzTXESdQ3bxE-q9uLu-Bm9d/view?usp=sharing Syzlang reproducer: https://drive.google.com/file/d/18wnwTf53Ln4K8e4G9d8hS4-e0URQKHet/view?usp=sharing C reproducer: https://drive.google.com/file/d/1ttiMq0WYi46zFP1II8O9eee_dvDweIb6/view?usp=sharing kernel config: https://drive.google.com/file/d/1fITkvcuglspvuhI0mhXUndx112fJmcOZ/view?usp=sharing IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: Wei Chen <harperchen1110@xxxxxxxxx> BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 12f83067 P4D 12f83067 PUD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.18.0-rc6 #12 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__list_del_entry_valid+0x26/0x80 Code: 00 00 00 00 55 48 89 e5 48 89 fe 48 ba 00 01 00 00 00 00 ad de 48 8b 0f 48 39 d1 74 22 48 8b 46 08 48 83 c2 22 48 39 d0 74 25 <48> 8b 10 48 39 f2 75 2d 48 8b 51 08 48 39 f2 75 37 b0 01 5d c3 48 RSP: 0018:ffff888007313720 EFLAGS: 00010217 RAX: 0000000000000000 RBX: ffff88800c6283e8 RCX: 0000000000000000 RDX: dead000000000122 RSI: ffff88800c6283e8 RDI: ffff88800c6283e8 RBP: ffff888007313720 R08: ffffffff84399732 R09: ffffffff84392a74 R10: 0000000000000042 R11: ffff8880072a2f80 R12: ffff8880138be238 R13: ffff888016cdb000 R14: ffff888016cdb5a0 R15: ffff888016cdb000 FS: 0000000000000000(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000012f82000 CR4: 0000000000750ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> sctp_sched_dequeue_common+0x1c/0x90 sctp_sched_prio_dequeue+0x67/0x80 __sctp_outq_teardown+0x299/0x380 sctp_outq_free+0x15/0x20 sctp_association_free+0xc3/0x440 sctp_do_sm+0x1ca7/0x2210 sctp_assoc_bh_rcv+0x1f6/0x340 sctp_inq_push+0x98/0xb0 sctp_rcv+0x134e/0x16b0 sctp6_rcv+0x1b/0x30 ip6_protocol_deliver_rcu+0x5b7/0x930 ip6_input+0x80/0x140 ip6_rcv_finish+0x16e/0x1d0 ipv6_rcv+0x72/0x110 __netif_receive_skb+0x66/0x140 process_backlog+0x13d/0x230 __napi_poll+0x4b/0x310 net_rx_action+0x1ae/0x410 __do_softirq+0x16e/0x30f run_ksoftirqd+0x23/0x30 smpboot_thread_fn+0x210/0x370 kthread+0x124/0x160 ret_from_fork+0x1f/0x30 </TASK> Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid+0x26/0x80 Code: 00 00 00 00 55 48 89 e5 48 89 fe 48 ba 00 01 00 00 00 00 ad de 48 8b 0f 48 39 d1 74 22 48 8b 46 08 48 83 c2 22 48 39 d0 74 25 <48> 8b 10 48 39 f2 75 2d 48 8b 51 08 48 39 f2 75 37 b0 01 5d c3 48 RSP: 0018:ffff888007313720 EFLAGS: 00010217 RAX: 0000000000000000 RBX: ffff88800c6283e8 RCX: 0000000000000000 RDX: dead000000000122 RSI: ffff88800c6283e8 RDI: ffff88800c6283e8 RBP: ffff888007313720 R08: ffffffff84399732 R09: ffffffff84392a74 R10: 0000000000000042 R11: ffff8880072a2f80 R12: ffff8880138be238 R13: ffff888016cdb000 R14: ffff888016cdb5a0 R15: ffff888016cdb000 FS: 0000000000000000(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000012f82000 CR4: 0000000000750ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 55 push %rbp 5: 48 89 e5 mov %rsp,%rbp 8: 48 89 fe mov %rdi,%rsi b: 48 ba 00 01 00 00 00 movabs $0xdead000000000100,%rdx 12: 00 ad de 15: 48 8b 0f mov (%rdi),%rcx 18: 48 39 d1 cmp %rdx,%rcx 1b: 74 22 je 0x3f 1d: 48 8b 46 08 mov 0x8(%rsi),%rax 21: 48 83 c2 22 add $0x22,%rdx 25: 48 39 d0 cmp %rdx,%rax 28: 74 25 je 0x4f * 2a: 48 8b 10 mov (%rax),%rdx <-- trapping instruction 2d: 48 39 f2 cmp %rsi,%rdx 30: 75 2d jne 0x5f 32: 48 8b 51 08 mov 0x8(%rcx),%rdx 36: 48 39 f2 cmp %rsi,%rdx 39: 75 37 jne 0x72 3b: b0 01 mov $0x1,%al 3d: 5d pop %rbp 3e: c3 retq 3f: 48 rex.W
