{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23143","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:45.973Z","datePublished":"2026-02-14T15:36:08.834Z","dateUpdated":"2026-05-11T22:00:57.932Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:00:57.932Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio_net: Fix misalignment bug in struct virtnet_info\n\nUse the new TRAILING_OVERLAP() helper to fix a misalignment bug\nalong with the following warning:\n\ndrivers/net/virtio_net.c:429:46: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]\n\nThis helper creates a union between a flexible-array member (FAM)\nand a set of members that would otherwise follow it (in this case\n`u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE];`). This\noverlays the trailing members (rss_hash_key_data) onto the FAM\n(hash_key_data) while keeping the FAM and the start of MEMBERS aligned.\nThe static_assert() ensures this alignment remains.\n\nNotice that due to tail padding in flexible `struct\nvirtio_net_rss_config_trailer`, `rss_trailer.hash_key_data`\n(at offset 83 in struct virtnet_info) and `rss_hash_key_data` (at\noffset 84 in struct virtnet_info) are misaligned by one byte. See\nbelow:\n\nstruct virtio_net_rss_config_trailer {\n        __le16                     max_tx_vq;            /*     0     2 */\n        __u8                       hash_key_length;      /*     2     1 */\n        __u8                       hash_key_data[];      /*     3     0 */\n\n        /* size: 4, cachelines: 1, members: 3 */\n        /* padding: 1 */\n        /* last cacheline: 4 bytes */\n};\n\nstruct virtnet_info {\n...\n        struct virtio_net_rss_config_trailer rss_trailer; /*    80     4 */\n\n        /* XXX last struct has 1 byte of padding */\n\n        u8                         rss_hash_key_data[40]; /*    84    40 */\n...\n        /* size: 832, cachelines: 13, members: 48 */\n        /* sum members: 801, holes: 8, sum holes: 31 */\n        /* paddings: 2, sum paddings: 5 */\n};\n\nAfter changes, those members are correctly aligned at offset 795:\n\nstruct virtnet_info {\n...\n        union {\n                struct virtio_net_rss_config_trailer rss_trailer; /*   792     4 */\n                struct {\n                        unsigned char __offset_to_hash_key_data[3]; /*   792     3 */\n                        u8         rss_hash_key_data[40]; /*   795    40 */\n                };                                       /*   792    43 */\n        };                                               /*   792    44 */\n...\n        /* size: 840, cachelines: 14, members: 47 */\n        /* sum members: 801, holes: 8, sum holes: 35 */\n        /* padding: 4 */\n        /* paddings: 1, sum paddings: 4 */\n        /* last cacheline: 8 bytes */\n};\n\nAs a result, the RSS key passed to the device is shifted by 1\nbyte: the last byte is cut off, and instead a (possibly\nuninitialized) byte is added at the beginning.\n\nAs a last note `struct virtio_net_rss_config_hdr *rss_hdr;` is also\nmoved to the end, since it seems those three members should stick\naround together. :)"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/virtio_net.c"],"versions":[{"version":"ed3100e90d0d120a045a551b85eb43cf2527e885","lessThan":"ae48108c2310f1dd700e0dbb655c2f1d92ed00fc","status":"affected","versionType":"git"},{"version":"ed3100e90d0d120a045a551b85eb43cf2527e885","lessThan":"4156c3745f06bc197094b9ee97a9584e69ed00bf","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/virtio_net.c"],"versions":[{"version":"6.15","status":"affected"},{"version":"0","lessThan":"6.15","status":"unaffected","versionType":"semver"},{"version":"6.18.7","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19","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":"6.15","versionEndExcluding":"6.18.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.19"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/ae48108c2310f1dd700e0dbb655c2f1d92ed00fc"},{"url":"https://git.kernel.org/stable/c/4156c3745f06bc197094b9ee97a9584e69ed00bf"}],"title":"virtio_net: Fix misalignment bug in struct virtnet_info","x_generator":{"engine":"bippy-1.2.0"}}}}