{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-64188", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-64188" ], "published": "2026-07-20T16:28:05Z", "summary": "net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()\n\nrmnet_dellink() removes the endpoint from the hash table with\nhlist_del_init_rcu() and then immediately frees it with kfree(). However,\nRCU readers on the receive path (rmnet_rx_handler ->\n__rmnet_map_ingress_handler) may still hold a reference to the endpoint and\ndereference ep->egress_dev after the memory has been freed. The endpoint is\na kmalloc-32 object, and the stale read at offset 8 corresponds to the\negress_dev pointer.\n\n BUG: unable to handle page fault for address: ffffffffde942eef\n Oops: 0002 [#1] SMP NOPTI\n CPU: 1 UID: 0 PID: 137 Comm: poc_write Not tainted 7.0.0+ #4 PREEMPTLAZY\n RIP: 0010:rmnet_vnd_rx_fixup (rmnet_vnd.c:27)\n Call Trace:\n \n __rmnet_map_ingress_handler (rmnet_handlers.c:48 rmnet_handlers.c:101)\n rmnet_rx_handler (rmnet_handlers.c:129 rmnet_handlers.c:235)\n __netif_receive_skb_core.constprop.0 (net/core/dev.c:6096)\n __netif_receive_skb_one_core (net/core/dev.c:6208)\n netif_receive_skb (net/core/dev.c:6467)\n tun_get_user (drivers/net/tun.c:1955)\n tun_chr_write_iter (drivers/net/tun.c:2003)\n vfs_write (fs/read_write.c:688)\n ksys_write (fs/read_write.c:740)\n \n\nAdd an rcu_head field to struct rmnet_endpoint and replace kfree() with\nkfree_rcu() so the endpoint memory remains valid through the RCU grace\nperiod. Also remove the rmnet_vnd_dellink() call and inline only the\nnr_rmnet_devs decrement, since rmnet_vnd_dellink() would set\nep->egress_dev to NULL during the grace period, creating a data race\nwith lockless readers.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.177", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-64188" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c4e676c3505c5058922dc1a6f1ded795f6758135" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9918698cf3aee4032e12bb42fd5a951dc465339b" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/310b93246bfec7d4452507e0c15477377ed9f025" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1078ae8175777e80c9637996fb4a46c55f0ce576" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/41e06fcc5df0774d212e70c5b503fc769492bce3" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/8b17adf6d4fb6bf61fa4c3f58366a7c082799a71" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f193e38cb257d033060b63f1cfd94af076b3a2ab" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/d00c953a8f69921f484b629801766da68f27f658" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T13:16:28Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The complete exploit path is local: attacker-written frames enter through TUN while RTM_DELLINK over NETLINK_ROUTE invokes rmnet_dellink(); remote traffic alone cannot perform the required endpoint deletion.\nAC:L - The attacker controls both sides of the race by concurrently injecting crafted MAP frames and deleting or recreating the RMNET link, allowing repeated attempts without an uncontrollable condition.\nPR:L - Deletion requires CAP_NET_ADMIN in the route socket's network namespace, which an unprivileged user can obtain through a private user and network namespace to create TUN and RMNET devices.\nUI:N - No separate victim action is required because the attacker directly performs link setup, packet injection, and deletion.\nS:U - Exploitation compromises the kernel within the same security authority and does not cross a VM, IOMMU, or comparable scope boundary.\nC:H - The freed kmalloc-32 endpoint can be reclaimed with attacker-influenced contents, making the stale egress_dev pointer usable for forged-object dereferences and access to sensitive kernel memory.\nI:H - The corrupted egress_dev pointer reaches rmnet_vnd_rx_fixup, where derived per-CPU statistics pointers are written, providing a plausible path to arbitrary memory corruption and control-flow hijacking.\nA:H - The demonstrated race causes a page fault and kernel Oops in rmnet_vnd_rx_fixup, and it can be triggered repeatedly to crash the system." } } }