{"id":"CVE-2026-74678","state":"PUBLISHED","title":"net: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()\n\nWhen the interface has NETIF_F_SG enabled and skb_linearize() fails in\nax88179_tx_fixup(), the function returns NULL without freeing the skb.\n\nusbnet_start_xmit() treats a NULL return from tx_fixup() as a drop\n(info->flags does not set FLAG_MULTI_PACKET for this driver), jumping\nto the \"drop\" label where it does `if (skb) dev_kfree_skb_any(skb)`.\nBecause tx_fixup() returned NULL, the local skb variable in\nusbnet_start_xmit() is NULL, so the original skb is never freed — a\nmemory leak on every TX frame whose linearization fails (i.e. under\nmemory pressure).\n\nFree the skb before returning, matching the error handling already used\nfor the pskb_expand_head() failure path in the same function.","publishedAt":"2026-08-22T15:32:46.765Z","updatedAt":"2026-10-16T19:16:08.884Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"83a765cbd7b4d11b0b9fa1bb9d941ae911a2159b","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"1c63303659a2264bd55d9813df74cb4caeed5922","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"2be5091fa693b9119ad25a8bb8c149d236a23ade","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"58733b1dd46bb231d9d279c132a20ee46da1b664","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"4039cd807a5a46dc5f7618fffae926b8ad8455eb","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"1f428e30947395d9b9aacee03e25a4e6cfcad7a4","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/usb/ax88179_178a.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/usb/ax88179_178a.c"]}],"references":["https://git.kernel.org/stable/c/83a765cbd7b4d11b0b9fa1bb9d941ae911a2159b","https://git.kernel.org/stable/c/1c63303659a2264bd55d9813df74cb4caeed5922","https://git.kernel.org/stable/c/2be5091fa693b9119ad25a8bb8c149d236a23ade","https://git.kernel.org/stable/c/58733b1dd46bb231d9d279c132a20ee46da1b664","https://git.kernel.org/stable/c/4039cd807a5a46dc5f7618fffae926b8ad8455eb","https://git.kernel.org/stable/c/1f428e30947395d9b9aacee03e25a4e6cfcad7a4"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74678.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74678","state":"PUBLISHED","datePublished":"2026-08-22T15:32:46.765Z","dateUpdated":"2026-10-16T19:16:08.884Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.925Z"},"containers":{"cna":{"title":"net: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: usb: ax88179_178a: fix skb leak in ax88179_tx_fixup()\n\nWhen the interface has NETIF_F_SG enabled and skb_linearize() fails in\nax88179_tx_fixup(), the function returns NULL without freeing the skb.\n\nusbnet_start_xmit() treats a NULL return from tx_fixup() as a drop\n(info->flags does not set FLAG_MULTI_PACKET for this driver), jumping\nto the \"drop\" label where it does `if (skb) dev_kfree_skb_any(skb)`.\nBecause tx_fixup() returned NULL, the local skb variable in\nusbnet_start_xmit() is NULL, so the original skb is never freed — a\nmemory leak on every TX frame whose linearization fails (i.e. under\nmemory pressure).\n\nFree the skb before returning, matching the error handling already used\nfor the pskb_expand_head() failure path in the same function."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"83a765cbd7b4d11b0b9fa1bb9d941ae911a2159b","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"1c63303659a2264bd55d9813df74cb4caeed5922","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"2be5091fa693b9119ad25a8bb8c149d236a23ade","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"58733b1dd46bb231d9d279c132a20ee46da1b664","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"4039cd807a5a46dc5f7618fffae926b8ad8455eb","versionType":"git"},{"version":"16b1c4e01c89ba07367461e0bc4cb84993c2d027","status":"affected","lessThan":"1f428e30947395d9b9aacee03e25a4e6cfcad7a4","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/usb/ax88179_178a.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.152","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.104","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/usb/ax88179_178a.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/83a765cbd7b4d11b0b9fa1bb9d941ae911a2159b"},{"url":"https://git.kernel.org/stable/c/1c63303659a2264bd55d9813df74cb4caeed5922"},{"url":"https://git.kernel.org/stable/c/2be5091fa693b9119ad25a8bb8c149d236a23ade"},{"url":"https://git.kernel.org/stable/c/58733b1dd46bb231d9d279c132a20ee46da1b664"},{"url":"https://git.kernel.org/stable/c/4039cd807a5a46dc5f7618fffae926b8ad8455eb"},{"url":"https://git.kernel.org/stable/c/1f428e30947395d9b9aacee03e25a4e6cfcad7a4"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - On systems using the common ASIX AX88179/AX88178A USB 3.0 GbE adapter as their uplink, remote peers induce outbound TSO/GSO traffic that reaches ax88179_tx_fixup() via __dev_queue_xmit→netdev_start_xmit→usbnet_start_xmit; attacker-supplied or reply traffic over the bound NIC is standard network reachability.\nAC:L - NETIF_F_SG and NETIF_F_TSO are always enabled at bind; an attacker can send non-linear egress skbs and deliberately exhaust GFP_ATOMIC/slab memory so skb_linearize() fails on demand—both prerequisites are fully under attacker control without races or rare layout.\nPR:N - No capability or authentication gates the netdev TX path; any remote host exchanging IP traffic with a victim whose ax88179 interface is up can trigger usbnet_start_xmit without local shell access, credentials, or init-namespace privileges.\nUI:N - Exploitation needs only that the adapter is plugged in and carrying traffic—the normal always-on state for USB-Ethernet docks, kiosks, and laptops—not any one-time victim action such as mounting media or opening a file.\nS:U - Leaked sk_buff objects remain in kernel SLAB caches within the same kernel security authority; there is no VM escape, container breakout, IOMMU bypass, or cross-boundary corruption.\nC:N - Orphaned skbs are not freed but are not exposed to userspace or adjacent objects; there is no out-of-bounds read, use-after-free, or other disclosure primitive—only silent kernel heap consumption.\nI:N - The defect drops an skb reference on an error return without corrupting heap metadata, overwriting kernel objects, or enabling arbitrary writes or control-flow hijacking.\nA:H - Each skb_linearize() failure permanently leaks one skb; under attacker-driven memory pressure an unauthenticated remote peer can repeat TSO egress to exhaust kernel memory, provoking OOM-killer thrashing and denial of service on the 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