CVE-2024-26615

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net/smc: fix illegal rmb_desc access in SMC-D connection dump<br /> <br /> A crash was found when dumping SMC-D connections. It can be reproduced<br /> by following steps:<br /> <br /> - run nginx/wrk test:<br /> smc_run nginx<br /> smc_run wrk -t 16 -c 1000 -d -H &amp;#39;Connection: Close&amp;#39; <br /> <br /> - continuously dump SMC-D connections in parallel:<br /> watch -n 1 &amp;#39;smcss -D&amp;#39;<br /> <br /> BUG: kernel NULL pointer dereference, address: 0000000000000030<br /> CPU: 2 PID: 7204 Comm: smcss Kdump: loaded Tainted: G E 6.7.0+ #55<br /> RIP: 0010:__smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]<br /> Call Trace:<br /> <br /> ? __die+0x24/0x70<br /> ? page_fault_oops+0x66/0x150<br /> ? exc_page_fault+0x69/0x140<br /> ? asm_exc_page_fault+0x26/0x30<br /> ? __smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]<br /> ? __kmalloc_node_track_caller+0x35d/0x430<br /> ? __alloc_skb+0x77/0x170<br /> smc_diag_dump_proto+0xd0/0xf0 [smc_diag]<br /> smc_diag_dump+0x26/0x60 [smc_diag]<br /> netlink_dump+0x19f/0x320<br /> __netlink_dump_start+0x1dc/0x300<br /> smc_diag_handler_dump+0x6a/0x80 [smc_diag]<br /> ? __pfx_smc_diag_dump+0x10/0x10 [smc_diag]<br /> sock_diag_rcv_msg+0x121/0x140<br /> ? __pfx_sock_diag_rcv_msg+0x10/0x10<br /> netlink_rcv_skb+0x5a/0x110<br /> sock_diag_rcv+0x28/0x40<br /> netlink_unicast+0x22a/0x330<br /> netlink_sendmsg+0x1f8/0x420<br /> __sock_sendmsg+0xb0/0xc0<br /> ____sys_sendmsg+0x24e/0x300<br /> ? copy_msghdr_from_user+0x62/0x80<br /> ___sys_sendmsg+0x7c/0xd0<br /> ? __do_fault+0x34/0x160<br /> ? do_read_fault+0x5f/0x100<br /> ? do_fault+0xb0/0x110<br /> ? __handle_mm_fault+0x2b0/0x6c0<br /> __sys_sendmsg+0x4d/0x80<br /> do_syscall_64+0x69/0x180<br /> entry_SYSCALL_64_after_hwframe+0x6e/0x76<br /> <br /> It is possible that the connection is in process of being established<br /> when we dump it. Assumed that the connection has been registered in a<br /> link group by smc_conn_create() but the rmb_desc has not yet been<br /> initialized by smc_buf_create(), thus causing the illegal access to<br /> conn-&gt;rmb_desc. So fix it by checking before dump.