openvswitch: cap upcall PID array size and pre-size vport replies
In the Linux kernel, the following vulnerability has been resolved: openvswitch: cap upcall PID array size and pre-size vport replies The vport netlink reply helpers allocate a fixed-size skb with nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID array via ovs_vport_get_upcall_portids(). Since ovs_vport_set_upcall_portids() accepts any non-zero multiple of sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID array large enough to overflow the reply buffer, causing nla_put() to fail with -EMSGSIZE and hitting BUG_ON(err < 0). On systems with unprivileged user namespaces enabled (e.g., Ubuntu default), this is reachable via unshare -Urn since OVS vport mutation operations use GENL_UNS_ADMIN_PERM. kernel BUG at net/openvswitch/datapath.c:2414! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1 RIP: 0010:ovs_vport_cmd_set+0x34c/0x400 Call Trace: genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116) genl_rcv_msg (net/netlink/genetlink.c:1194) netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/genetlink.c:1219) netlink_unicast (net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sys_sendto (net/socket.c:2206) __x64_sys_sendto (net/socket.c:2209) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Kernel panic - not syncing: Fatal exception Reject attempts to set mor
CVE-2026-45840
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-45840
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "8d59b80e69dddb665eb2de36e62859ab2073470e",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "d9e47e29aacb9f8a9d59feb6ab5b128a9bbb40b0",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "b39f763d720d623218bc1d95ace6855d7b474e81",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "f9ef3db77a383d66847fd082c2b437d8ae4d9c63",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "f99ac36b5d7c719d08a69fcdecce40f78a874e15",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "fa6e90bc443bed8dc0d55bc5ea5b27ffdfe37704",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "1d6c02b86329883aa467a3a61f8d34369db73a2f",
"versionType": "git"
},
{
"status": "affected",
"version": "5cd667b0a4567048bb555927d6ee564f4e5620a9",
"lessThan": "2091c6aa0df6aba47deb5c8ab232b1cb60af3519",
"versionType": "git"
}
],
"programFiles": [
"net/openvswitch/datapath.c",
"net/openvswitch/vport.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.141",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/datapath.c",
"net/openvswitch/vport.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-45840
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #28364 · Revision 1
- Added to Heist Feed
- Publisher date