{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45840","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.077Z","datePublished":"2026-05-27T09:24:39.478Z","dateUpdated":"2026-06-14T17:46:11.287Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-14T17:46:11.287Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nopenvswitch: cap upcall PID array size and pre-size vport replies\n\nThe vport netlink reply helpers allocate a fixed-size skb with\nnlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID\narray via ovs_vport_get_upcall_portids().  Since\novs_vport_set_upcall_portids() accepts any non-zero multiple of\nsizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID\narray large enough to overflow the reply buffer, causing nla_put() to\nfail with -EMSGSIZE and hitting BUG_ON(err < 0).  On systems with\nunprivileged user namespaces enabled (e.g., Ubuntu default), this is\nreachable via unshare -Urn since OVS vport mutation operations use\nGENL_UNS_ADMIN_PERM.\n\n kernel BUG at net/openvswitch/datapath.c:2414!\n Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1\n RIP: 0010:ovs_vport_cmd_set+0x34c/0x400\n Call Trace:\n  <TASK>\n  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)\n  genl_rcv_msg (net/netlink/genetlink.c:1194)\n  netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n  genl_rcv (net/netlink/genetlink.c:1219)\n  netlink_unicast (net/netlink/af_netlink.c:1344)\n  netlink_sendmsg (net/netlink/af_netlink.c:1894)\n  __sys_sendto (net/socket.c:2206)\n  __x64_sys_sendto (net/socket.c:2209)\n  do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n  </TASK>\n Kernel panic - not syncing: Fatal exception\n\nReject attempts to set more PIDs than nr_cpu_ids in\novs_vport_set_upcall_portids(), and pre-compute the worst-case reply\nsize in ovs_vport_cmd_msg_size() based on that bound, similar to the\nexisting ovs_dp_cmd_msg_size().  nr_cpu_ids matches the cap already\nused by the per-CPU dispatch configuration on the datapath side\n(ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the\ntwo sides stay consistent."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c","net/openvswitch/vport.c"],"versions":[{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"8d59b80e69dddb665eb2de36e62859ab2073470e","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"d9e47e29aacb9f8a9d59feb6ab5b128a9bbb40b0","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"b39f763d720d623218bc1d95ace6855d7b474e81","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"f9ef3db77a383d66847fd082c2b437d8ae4d9c63","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"f99ac36b5d7c719d08a69fcdecce40f78a874e15","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"fa6e90bc443bed8dc0d55bc5ea5b27ffdfe37704","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"1d6c02b86329883aa467a3a61f8d34369db73a2f","status":"affected","versionType":"git"},{"version":"5cd667b0a4567048bb555927d6ee564f4e5620a9","lessThan":"2091c6aa0df6aba47deb5c8ab232b1cb60af3519","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c","net/openvswitch/vport.c"],"versions":[{"version":"3.17","status":"affected"},{"version":"0","lessThan":"3.17","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"3.17","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.17","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/8d59b80e69dddb665eb2de36e62859ab2073470e"},{"url":"https://git.kernel.org/stable/c/d9e47e29aacb9f8a9d59feb6ab5b128a9bbb40b0"},{"url":"https://git.kernel.org/stable/c/b39f763d720d623218bc1d95ace6855d7b474e81"},{"url":"https://git.kernel.org/stable/c/f9ef3db77a383d66847fd082c2b437d8ae4d9c63"},{"url":"https://git.kernel.org/stable/c/f99ac36b5d7c719d08a69fcdecce40f78a874e15"},{"url":"https://git.kernel.org/stable/c/fa6e90bc443bed8dc0d55bc5ea5b27ffdfe37704"},{"url":"https://git.kernel.org/stable/c/1d6c02b86329883aa467a3a61f8d34369db73a2f"},{"url":"https://git.kernel.org/stable/c/2091c6aa0df6aba47deb5c8ab232b1cb60af3519"}],"title":"openvswitch: cap upcall PID array size and pre-size vport replies","x_generator":{"engine":"bippy-1.2.0"}}}}