CVE-2025-39857

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync()<br /> <br /> BUG: kernel NULL pointer dereference, address: 00000000000002ec<br /> PGD 0 P4D 0<br /> Oops: Oops: 0000 [#1] SMP PTI<br /> CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE<br /> Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014<br /> Workqueue: smc_hs_wq smc_listen_work [smc]<br /> RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc]<br /> ...<br /> Call Trace:<br /> <br /> smcr_buf_map_link+0x211/0x2a0 [smc]<br /> __smc_buf_create+0x522/0x970 [smc]<br /> smc_buf_create+0x3a/0x110 [smc]<br /> smc_find_rdma_v2_device_serv+0x18f/0x240 [smc]<br /> ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc]<br /> smc_listen_find_device+0x1dd/0x2b0 [smc]<br /> smc_listen_work+0x30f/0x580 [smc]<br /> process_one_work+0x18c/0x340<br /> worker_thread+0x242/0x360<br /> kthread+0xe7/0x220<br /> ret_from_fork+0x13a/0x160<br /> ret_from_fork_asm+0x1a/0x30<br /> <br /> <br /> If the software RoCE device is used, ibdev-&gt;dma_device is a null pointer.<br /> As a result, the problem occurs. Null pointer detection is added to<br /> prevent problems.