CVE-2023-52889

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> apparmor: Fix null pointer deref when receiving skb during sock creation<br /> <br /> The panic below is observed when receiving ICMP packets with secmark set<br /> while an ICMP raw socket is being created. SK_CTX(sk)-&gt;label is updated<br /> in apparmor_socket_post_create(), but the packet is delivered to the<br /> socket before that, causing the null pointer dereference.<br /> Drop the packet if label context is not set.<br /> <br /> BUG: kernel NULL pointer dereference, address: 000000000000004c<br /> #PF: supervisor read access in kernel mode<br /> #PF: error_code(0x0000) - not-present page<br /> PGD 0 P4D 0<br /> Oops: 0000 [#1] PREEMPT SMP NOPTI<br /> CPU: 0 PID: 407 Comm: a.out Not tainted 6.4.12-arch1-1 #1 3e6fa2753a2d75925c34ecb78e22e85a65d083df<br /> Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/28/2020<br /> RIP: 0010:aa_label_next_confined+0xb/0x40<br /> Code: 00 00 48 89 ef e8 d5 25 0c 00 e9 66 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 89 f0 77 4c 39 c6 7e 1f 48 63 d0 48 8d 14 d7 eb 0b 83 c0 01 48 83 c2<br /> RSP: 0018:ffffa92940003b08 EFLAGS: 00010246<br /> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000000e<br /> RDX: ffffa92940003be8 RSI: 0000000000000000 RDI: 0000000000000000<br /> RBP: ffff8b57471e7800 R08: ffff8b574c642400 R09: 0000000000000002<br /> R10: ffffffffbd820eeb R11: ffffffffbeb7ff00 R12: ffff8b574c642400<br /> R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000<br /> FS: 00007fb092ea7640(0000) GS:ffff8b577bc00000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 000000000000004c CR3: 00000001020f2005 CR4: 00000000007706f0<br /> PKRU: 55555554<br /> Call Trace:<br /> <br /> ? __die+0x23/0x70<br /> ? page_fault_oops+0x171/0x4e0<br /> ? exc_page_fault+0x7f/0x180<br /> ? asm_exc_page_fault+0x26/0x30<br /> ? aa_label_next_confined+0xb/0x40<br /> apparmor_secmark_check+0xec/0x330<br /> security_sock_rcv_skb+0x35/0x50<br /> sk_filter_trim_cap+0x47/0x250<br /> sock_queue_rcv_skb_reason+0x20/0x60<br /> raw_rcv+0x13c/0x210<br /> raw_local_deliver+0x1f3/0x250<br /> ip_protocol_deliver_rcu+0x4f/0x2f0<br /> ip_local_deliver_finish+0x76/0xa0<br /> __netif_receive_skb_one_core+0x89/0xa0<br /> netif_receive_skb+0x119/0x170<br /> ? __netdev_alloc_skb+0x3d/0x140<br /> vmxnet3_rq_rx_complete+0xb23/0x1010 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a]<br /> vmxnet3_poll_rx_only+0x36/0xb0 [vmxnet3 56a84f9c97178c57a43a24ec073b45a9d6f01f3a]<br /> __napi_poll+0x28/0x1b0<br /> net_rx_action+0x2a4/0x380<br /> __do_softirq+0xd1/0x2c8<br /> __irq_exit_rcu+0xbb/0xf0<br /> common_interrupt+0x86/0xa0<br /> <br /> <br /> asm_common_interrupt+0x26/0x40<br /> RIP: 0010:apparmor_socket_post_create+0xb/0x200<br /> Code: 08 48 85 ff 75 a1 eb b1 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 41 54 48 89 fd 53 45 85 c0 0f 84 b2 00 00 00 48 8b 1d 80 56 3f 02 48<br /> RSP: 0018:ffffa92940ce7e50 EFLAGS: 00000286<br /> RAX: ffffffffbc756440 RBX: 0000000000000000 RCX: 0000000000000001<br /> RDX: 0000000000000003 RSI: 0000000000000002 RDI: ffff8b574eaab740<br /> RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000<br /> R10: ffff8b57444cec70 R11: 0000000000000000 R12: 0000000000000003<br /> R13: 0000000000000002 R14: ffff8b574eaab740 R15: ffffffffbd8e4748<br /> ? __pfx_apparmor_socket_post_create+0x10/0x10<br /> security_socket_post_create+0x4b/0x80<br /> __sock_create+0x176/0x1f0<br /> __sys_socket+0x89/0x100<br /> __x64_sys_socket+0x17/0x20<br /> do_syscall_64+0x5d/0x90<br /> ? do_syscall_64+0x6c/0x90<br /> ? do_syscall_64+0x6c/0x90<br /> ? do_syscall_64+0x6c/0x90<br /> entry_SYSCALL_64_after_hwframe+0x72/0xdc