{"id":"CVE-2023-53843","state":"PUBLISHED","title":"net: openvswitch: reject negative ifindex","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: reject negative ifindex\n\nRecent changes in net-next (commit 759ab1edb56c (\"net: store netdevs\nin an xarray\")) refactored the handling of pre-assigned ifindexes\nand let syzbot surface a latent problem in ovs. ovs does not validate\nifindex, making it possible to create netdev ports with negative\nifindex values. It's easy to repro with YNL:\n\n$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \\\n         --do new \\\n\t --json '{\"upcall-pid\": 1, \"name\":\"my-dp\"}'\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n\n$ ip link show\n-65536: some-port0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000\n    link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff\n...\n\nValidate the inputs. Now the second command correctly returns:\n\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n\nlib.ynl.NlError: Netlink error: Numerical result out of range\nnl_len = 108 (92) nl_flags = 0x300 nl_type = 2\n\terror: -34\textack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\\x0c\\x00\\x02\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0c\\x00\\x03\\x00\\xff\\xff\\xff\\x7f\\x00\\x00\\x00\\x00\\x08\\x00\\x01\\x00\\x08\\x00\\x00\\x00'], 'bad-attr': '.ifindex'}\n\nAccept 0 since it used to be silently ignored.","publishedAt":"2025-12-09T01:30:05.698Z","updatedAt":"2026-05-11T19:52:35.532Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"c965a58376146dcfdda186819462e8eb3aadef3a","versionType":"git"},{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"881faff9e548a7ddfb11595be7c1c649217d27db","versionType":"git"},{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"a552bfa16bab4ce901ee721346a28c4e483f4066","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.1","versionType":"semver"},{"version":"6.1.47","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.12","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c"]}],"references":["https://git.kernel.org/stable/c/c965a58376146dcfdda186819462e8eb3aadef3a","https://git.kernel.org/stable/c/881faff9e548a7ddfb11595be7c1c649217d27db","https://git.kernel.org/stable/c/a552bfa16bab4ce901ee721346a28c4e483f4066"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53843.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53843","state":"PUBLISHED","datePublished":"2025-12-09T01:30:05.698Z","dateUpdated":"2026-05-11T19:52:35.532Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-09T01:27:17.826Z"},"containers":{"cna":{"title":"net: openvswitch: reject negative ifindex","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: reject negative ifindex\n\nRecent changes in net-next (commit 759ab1edb56c (\"net: store netdevs\nin an xarray\")) refactored the handling of pre-assigned ifindexes\nand let syzbot surface a latent problem in ovs. ovs does not validate\nifindex, making it possible to create netdev ports with negative\nifindex values. It's easy to repro with YNL:\n\n$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \\\n         --do new \\\n\t --json '{\"upcall-pid\": 1, \"name\":\"my-dp\"}'\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n\n$ ip link show\n-65536: some-port0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000\n    link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff\n...\n\nValidate the inputs. Now the second command correctly returns:\n\n$ ./cli.py --spec netlink/specs/ovs_vport.yaml \\\n\t --do new \\\n\t --json '{\"upcall-pid\": \"00000001\", \"name\": \"some-port0\", \"dp-ifindex\":3,\"ifindex\":4294901760,\"type\":2}'\n\nlib.ynl.NlError: Netlink error: Numerical result out of range\nnl_len = 108 (92) nl_flags = 0x300 nl_type = 2\n\terror: -34\textack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\\x0c\\x00\\x02\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x0c\\x00\\x03\\x00\\xff\\xff\\xff\\x7f\\x00\\x00\\x00\\x00\\x08\\x00\\x01\\x00\\x08\\x00\\x00\\x00'], 'bad-attr': '.ifindex'}\n\nAccept 0 since it used to be silently ignored."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"c965a58376146dcfdda186819462e8eb3aadef3a","versionType":"git"},{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"881faff9e548a7ddfb11595be7c1c649217d27db","versionType":"git"},{"version":"54c4ef34c4b6f9720fded620e2893894f9f2c554","status":"affected","lessThan":"a552bfa16bab4ce901ee721346a28c4e483f4066","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.1","versionType":"semver"},{"version":"6.1.47","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.12","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/openvswitch/datapath.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c965a58376146dcfdda186819462e8eb3aadef3a"},{"url":"https://git.kernel.org/stable/c/881faff9e548a7ddfb11595be7c1c649217d27db"},{"url":"https://git.kernel.org/stable/c/a552bfa16bab4ce901ee721346a28c4e483f4066"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:52:35.532Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.1.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.4.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1","versionEndExcluding":"6.5"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}