{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-40290","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.185Z","datePublished":"2025-12-08T00:09:08.370Z","dateUpdated":"2026-08-05T12:09:16.273Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:09:16.273Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: avoid data corruption on cq descriptor number\n\nSince commit 30f241fcf52a (\"xsk: Fix immature cq descriptor\nproduction\"), the descriptor number is stored in skb control block and\nxsk_cq_submit_addr_locked() relies on it to put the umem addrs onto\npool's completion queue.\n\nskb control block shouldn't be used for this purpose as after transmit\nxsk doesn't have control over it and other subsystems could use it. This\nleads to the following kernel panic due to a NULL pointer dereference.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP NOPTI\n CPU: 2 UID: 1 PID: 927 Comm: p4xsk.bin Not tainted 6.16.12+deb14-cloud-amd64 #1 PREEMPT(lazy)  Debian 6.16.12-1\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n RIP: 0010:xsk_destruct_skb+0xd0/0x180\n [...]\n Call Trace:\n  <IRQ>\n  ? napi_complete_done+0x7a/0x1a0\n  ip_rcv_core+0x1bb/0x340\n  ip_rcv+0x30/0x1f0\n  __netif_receive_skb_one_core+0x85/0xa0\n  process_backlog+0x87/0x130\n  __napi_poll+0x28/0x180\n  net_rx_action+0x339/0x420\n  handle_softirqs+0xdc/0x320\n  ? handle_edge_irq+0x90/0x1e0\n  do_softirq.part.0+0x3b/0x60\n  </IRQ>\n  <TASK>\n  __local_bh_enable_ip+0x60/0x70\n  __dev_direct_xmit+0x14e/0x1f0\n  __xsk_generic_xmit+0x482/0xb70\n  ? __remove_hrtimer+0x41/0xa0\n  ? __xsk_generic_xmit+0x51/0xb70\n  ? _raw_spin_unlock_irqrestore+0xe/0x40\n  xsk_sendmsg+0xda/0x1c0\n  __sys_sendto+0x1ee/0x200\n  __x64_sys_sendto+0x24/0x30\n  do_syscall_64+0x84/0x2f0\n  ? __pfx_pollwake+0x10/0x10\n  ? __rseq_handle_notify_resume+0xad/0x4c0\n  ? restore_fpregs_from_fpstate+0x3c/0x90\n  ? switch_fpu_return+0x5b/0xe0\n  ? do_syscall_64+0x204/0x2f0\n  ? do_syscall_64+0x204/0x2f0\n  ? do_syscall_64+0x204/0x2f0\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n  </TASK>\n [...]\n Kernel panic - not syncing: Fatal exception in interrupt\n Kernel Offset: 0x1c000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)\n\nInstead use the skb destructor_arg pointer along with pointer tagging.\nAs pointers are always aligned to 8B, use the bottom bit to indicate\nwhether this a single address or an allocated struct containing several\naddresses."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is triggered by a local `sendto()`/`sendmsg()` syscall on an AF_XDP socket the attacker created and bound in generic (XDP_COPY) mode; no remote packet reception is involved in reaching the vulnerable destructor.\nAC:L - The attacker fully controls every precondition — creating the netns/veth pair, binding XDP_COPY to an interface with ifindex ≥ 2, and sending an IPv4/IPv6 frame — and the resulting `num_descs = ifindex > 1` plus zeroed list head is deterministic, not a race or a memory-layout gamble.\nPR:L - `xsk_create()` requires only `ns_capable(net->user_ns, CAP_NET_RAW)`, which any unprivileged user obtains via `unshare -Urn`, and the veth setup needs only CAP_NET_ADMIN in that same user namespace; the reported oops was hit by a non-root UID 1 process.\nUI:N - The attacking process performs the entire sequence itself — socket, umem, bind, sendmsg — with no action required from any other user or victim.\nS:U - The corruption and its impact are confined to the kernel's own security authority; no hypervisor, IOMMU, or other trust boundary is crossed.\nC:H - The wild list walk executes `xskq_prod_write_addr(pool->cq, ..., pos->addr)`, copying 8 bytes read from an uncontrolled kernel pointer into the completion ring that is mmap'd directly into the attacker's address space, giving a kernel-memory disclosure channel; the accompanying slab corruption further enables info-leak primitives.\nI:H - `list_del()` on the clobbered head performs two kernel writes through foreign pointers, and `kmem_cache_free(xsk_tx_generic_cache, pos)` frees a non-cache pointer into the wrong slab — an arbitrary-free/UAF primitive — plus the bogus count desyncs the shared completion queue via the unchecked `q->cached_prod -= cnt`.\nA:H - The reported and reproducible outcome is a NULL pointer dereference inside a softirq, producing `Kernel panic - not syncing: Fatal exception in interrupt` — a full system crash, repeatable at will by an unprivileged local user."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xdp/xsk.c"],"versions":[{"version":"30f241fcf52aaaef7ac16e66530faa11be78a865","lessThan":"c5ea2e50b5c9aa80c5b53526257540f0c26cd66d","status":"affected","versionType":"git"},{"version":"30f241fcf52aaaef7ac16e66530faa11be78a865","lessThan":"0ebc27a4c67d44e5ce88d21cdad8201862b78837","status":"affected","versionType":"git"},{"version":"932cb57e675a62982d4719e4b04e9f09a15a5baf","status":"affected","versionType":"git"},{"version":"6.16.8","lessThan":"6.17","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xdp/xsk.c"],"versions":[{"version":"6.17","status":"affected"},{"version":"0","lessThan":"6.17","status":"unaffected","versionType":"semver"},{"version":"6.17.11","lessThanOrEqual":"6.17.*","status":"unaffected","versionType":"semver"},{"version":"6.18","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.17.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.8"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/c5ea2e50b5c9aa80c5b53526257540f0c26cd66d"},{"url":"https://git.kernel.org/stable/c/0ebc27a4c67d44e5ce88d21cdad8201862b78837"},{"url":"https://bugs.debian.org/1118437"}],"title":"xsk: avoid data corruption on cq descriptor number","x_generator":{"engine":"bippy-1.2.0"}}}}