CVE-2023-52991

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: fix NULL pointer in skb_segment_list<br /> <br /> Commit 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.")<br /> introduced UDP listifyed GRO. The segmentation relies on frag_list being<br /> untouched when passing through the network stack. This assumption can be<br /> broken sometimes, where frag_list itself gets pulled into linear area,<br /> leaving frag_list being NULL. When this happens it can trigger<br /> following NULL pointer dereference, and panic the kernel. Reverse the<br /> test condition should fix it.<br /> <br /> [19185.577801][ C1] BUG: kernel NULL pointer dereference, address:<br /> ...<br /> [19185.663775][ C1] RIP: 0010:skb_segment_list+0x1cc/0x390<br /> ...<br /> [19185.834644][ C1] Call Trace:<br /> [19185.841730][ C1] <br /> [19185.848563][ C1] __udp_gso_segment+0x33e/0x510<br /> [19185.857370][ C1] inet_gso_segment+0x15b/0x3e0<br /> [19185.866059][ C1] skb_mac_gso_segment+0x97/0x110<br /> [19185.874939][ C1] __skb_gso_segment+0xb2/0x160<br /> [19185.883646][ C1] udp_queue_rcv_skb+0xc3/0x1d0<br /> [19185.892319][ C1] udp_unicast_rcv_skb+0x75/0x90<br /> [19185.900979][ C1] ip_protocol_deliver_rcu+0xd2/0x200<br /> [19185.910003][ C1] ip_local_deliver_finish+0x44/0x60<br /> [19185.918757][ C1] __netif_receive_skb_one_core+0x8b/0xa0<br /> [19185.927834][ C1] process_backlog+0x88/0x130<br /> [19185.935840][ C1] __napi_poll+0x27/0x150<br /> [19185.943447][ C1] net_rx_action+0x27e/0x5f0<br /> [19185.951331][ C1] ? mlx5_cq_tasklet_cb+0x70/0x160 [mlx5_core]<br /> [19185.960848][ C1] __do_softirq+0xbc/0x25d<br /> [19185.968607][ C1] irq_exit_rcu+0x83/0xb0<br /> [19185.976247][ C1] common_interrupt+0x43/0xa0<br /> [19185.984235][ C1] asm_common_interrupt+0x22/0x40<br /> ...<br /> [19186.094106][ C1]