{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72393","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-09T03:40:39.924Z","datePublished":"2026-08-15T05:56:21.081Z","dateUpdated":"2026-08-17T05:43:37.508Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:43:37.508Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\neth: fbnic: don't cache shinfo across skb realloc\n\nfbnic_tx_lso() calls skb_cow_head() which may reallocate the skb\nincluding the shared info. We can't use the pointer calculated\nbefore the call.\n\n    BUG: KASAN: slab-use-after-free in fbnic_tx_lso.isra.0+0x668/0x8e0\n    Read of size 4 at addr ff110000262edd98 by task swapper/5/0\n    Call Trace:\n     fbnic_tx_lso.isra.0+0x668/0x8e0\n     fbnic_xmit_frame+0x622/0xba0\n     dev_hard_start_xmit+0xf4/0x620\n\n    Allocated by task 8653:\n     __alloc_skb+0x11e/0x5f0\n     alloc_skb_with_frags+0xcc/0x6c0\n     sock_alloc_send_pskb+0x327/0x3f0\n     __ip_append_data+0x188b/0x47a0\n     ip_make_skb+0x24a/0x300\n     udp_sendmsg+0x14d2/0x21e0\n\n    Freed by task 0:\n     kfree+0x123/0x5a0\n     pskb_expand_head+0x36c/0xfa0\n     fbnic_tx_lso.isra.0+0x500/0x8e0\n     fbnic_xmit_frame+0x622/0xba0\n     dev_hard_start_xmit+0xf4/0x620\n     sch_direct_xmit+0x25b/0x1100\n\n    The buggy address belongs to the object at ff110000262edc40\n     which belongs to the cache skbuff_small_head of size 640\n    The buggy address is located 344 bytes inside of\n     freed 640-byte region [ff110000262edc40, ff110000262ede"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The bug is in fbnic_tx_lso on the outbound netdev path; KASAN shows udp_sendmsg→ip_make_skb→dev_hard_start_xmit. Remote peers can trigger GSO/USO/TSO transmits on internet-facing Meta hosts with fbnic (TCP responses or UDP USO), reaching the vulnerable driver without local access.\nAC:L - The USO selftest reliably reproduces the UAF when sending UDP_SEGMENT GSO skbs; attackers control MSS, payload size, and timing to force skb_cow_head/pskb_expand_head to reallocate the skb, making the stale shinfo dereference repeatable rather than dependent on uncontrollable state.\nPR:N - Triggering requires only standard unprivileged socket sendmsg with GSO/USO offload on a host using fbnic, or causing such outbound segmented traffic as an unauthenticated remote client; no CAP_NET_ADMIN, root, or special credentials are needed along the traced path.\nUI:N - Exploitation is fully attacker-driven through crafted network traffic or socket operations; no victim click, mount, or other voluntary action is required beyond normal always-on network service operation.\nS:U - Impact is kernel slab corruption and crash/privilege escalation within the host kernel security domain; it does not cross a VM/hypervisor or IOMMU boundary into a separate security authority.\nC:H - KASAN reports a slab use-after-free with a 4-byte read from freed skb_shared_info after pskb_expand_head; UAF of shinfo fields (gso_type, gso_size, gso_segs) enables heap grooming and arbitrary kernel memory disclosure.\nI:H - Use-after-free of skb_shared_info in the transmit LSO path is memory corruption in attacker-influenced heap objects; stale shinfo values drive metadata and checksum updates, enabling control of kernel data and potential code execution primitives.\nA:H - The reported KASAN slab-use-after-free in fbnic_tx_lso causes kernel oops/panic on transmit; repeated GSO/USO/TSO packets can crash or hang the system, denying availability on affected fbnic-equipped servers."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/meta/fbnic/fbnic_txrx.c"],"versions":[{"version":"b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1","lessThan":"83df3e2594cd78aa40b1246a19879abb4891945b","status":"affected","versionType":"git"},{"version":"b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1","lessThan":"21f304c2aae46625e050c28d979f4b9d83faa85e","status":"affected","versionType":"git"},{"version":"b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1","lessThan":"62b68b774f06bf52e329f254f0199bc43d350ccf","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/ethernet/meta/fbnic/fbnic_txrx.c"],"versions":[{"version":"6.15","status":"affected"},{"version":"0","lessThan":"6.15","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/83df3e2594cd78aa40b1246a19879abb4891945b"},{"url":"https://git.kernel.org/stable/c/21f304c2aae46625e050c28d979f4b9d83faa85e"},{"url":"https://git.kernel.org/stable/c/62b68b774f06bf52e329f254f0199bc43d350ccf"}],"title":"eth: fbnic: don't cache shinfo across skb realloc","x_generator":{"engine":"bippy-1.2.0"}}}}