CVE-2026-72393

{"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\u2192ip_make_skb\u2192dev_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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/ethernet/meta/fbnic/fbnic_txrx.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "83df3e2594cd78aa40b1246a19879abb4891945b", "status": "affected", "version": "b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1", "versionType": "git"}, {"lessThan": "21f304c2aae46625e050c28d979f4b9d83faa85e", "status": "affected", "version": "b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1", "versionType": "git"}, {"lessThan": "62b68b774f06bf52e329f254f0199bc43d350ccf", "status": "affected", "version": "b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/ethernet/meta/fbnic/fbnic_txrx.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"lessThan": "6.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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"}], "id": "CVE-2026-72393", "lastModified": "2026-08-17T06:19:05.793", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T06:22:12.847", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/21f304c2aae46625e050c28d979f4b9d83faa85e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/62b68b774f06bf52e329f254f0199bc43d350ccf"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/83df3e2594cd78aa40b1246a19879abb4891945b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: eth: fbnic: don't cache shinfo across skb realloc", "id": "2516557", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516557"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\neth: fbnic: don't cache shinfo across skb realloc\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.\nBUG: KASAN: slab-use-after-free in fbnic_tx_lso.isra.0+0x668/0x8e0\nRead of size 4 at addr ff110000262edd98 by task swapper/5/0\nCall Trace:\nfbnic_tx_lso.isra.0+0x668/0x8e0\nfbnic_xmit_frame+0x622/0xba0\ndev_hard_start_xmit+0xf4/0x620\nAllocated by task 8653:\n__alloc_skb+0x11e/0x5f0\nalloc_skb_with_frags+0xcc/0x6c0\nsock_alloc_send_pskb+0x327/0x3f0\n__ip_append_data+0x188b/0x47a0\nip_make_skb+0x24a/0x300\nudp_sendmsg+0x14d2/0x21e0\nFreed by task 0:\nkfree+0x123/0x5a0\npskb_expand_head+0x36c/0xfa0\nfbnic_tx_lso.isra.0+0x500/0x8e0\nfbnic_xmit_frame+0x622/0xba0\ndev_hard_start_xmit+0xf4/0x620\nsch_direct_xmit+0x25b/0x1100\nThe buggy address belongs to the object at ff110000262edc40\nwhich belongs to the cache skbuff_small_head of size 640\nThe buggy address is located 344 bytes inside of\nfreed 640-byte region [ff110000262edc40, ff110000262ede", "A flaw was found in the Linux kernel's fbnic Ethernet driver. When the fbnic_tx_lso() function reallocates a socket buffer (skb), it fails to update a cached pointer to shared information. This can lead to a use-after-free vulnerability, where the driver attempts to access memory that has already been released. This could result in a system crash, leading to a Denial of Service (DoS)."], "name": "CVE-2026-72393", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72393\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72393\nhttps://lore.kernel.org/linux-cve-announce/2026081520-CVE-2026-72393-158b@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1,83df3e2594cd78aa40b1246a19879abb4891945b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1,21f304c2aae46625e050c28d979f4b9d83faa85e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1,62b68b774f06bf52e329f254f0199bc43d350ccf)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T11:30:07.157946+00:00", "updated": "2026-08-22T07:00:07.562054+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-825"]}