{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-52943", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-52943", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-06-24T09:00:12.292Z", "updatedAt": "2026-10-19T19:47:08.739Z", "importedAt": "2026-10-24T01:58:14.884Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "net: skbuff: fix missing zerocopy reference in pskb_carve helpers", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: fix missing zerocopy reference in pskb_carve helpers\n\npskb_carve_inside_header() and pskb_carve_inside_nonlinear() both copy\nthe old skb_shared_info header into a new buffer via memcpy(), which\nincludes the destructor_arg pointer (uarg) for MSG_ZEROCOPY skbs.\nNeither function calls net_zcopy_get() for the new shinfo, creating an\nunaccounted holder: every skb_shared_info with destructor_arg set will\ncall skb_zcopy_clear() once when freed, but the corresponding\nnet_zcopy_get() was never called for the new copy. Repeated calls\ndrive uarg->refcnt to zero prematurely, freeing ubuf_info_msgzc while\nTX skbs still hold live destructor_arg pointers.\n\nKASAN reports use-after-free on a freed ubuf_info_msgzc:\n\n BUG: KASAN: slab-use-after-free in skb_release_data+0x77b/0x810\n Read of size 8 at addr ffff88801574d3e8 by task poc/220\n\n Call Trace:\n skb_release_data+0x77b/0x810\n kfree_skb_list_reason+0x13e/0x610\n skb_release_data+0x4cd/0x810\n sk_skb_reason_drop+0xf3/0x340\n skb_queue_purge_reason+0x282/0x440\n rds_tcp_inc_free+0x1e/0x30\n rds_recvmsg+0x354/0x1780\n __sys_recvmsg+0xdf/0x180\n\n Allocated by task 219:\n msg_zerocopy_realloc+0x157/0x7b0\n tcp_sendmsg_locked+0x2892/0x3ba0\n\n Freed by task 219:\n ip_recv_error+0x74a/0xb10\n tcp_recvmsg+0x475/0x530\n\nThe skb consuming the late access still referenced the same uarg via\nshinfo->destructor_arg copied by pskb_carve_inside_nonlinear() without\na refcount bump. This has been verified to be reliably exploitable: a\nworking proof-of-concept achieves full root privilege escalation from\nan unprivileged local user on a default kernel configuration.\n\nThe fix follows the pattern of pskb_expand_head() which has the same\nmemcpy/cloned structure. For pskb_carve_inside_header(), net_zcopy_get()\nis placed after skb_orphan_frags() succeeds, so the orphan error path\nneeds no cleanup. For pskb_carve_inside_nonlinear(), net_zcopy_get() is\nplaced after all failure points and just before skb_release_data(), so\nno error path needs cleanup at all -- matching pskb_expand_head() more\nclosely and avoiding the need for a balancing net_zcopy_put().", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "8dbed691e43a50903658130bde0fcb5abc425b37" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "9b40bdc2a3298225dffab8158208a0d8c6300578" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "fd470f0a97b8e9a125f520265d2f3b088ffb5b8a" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "ceafb893b12f23331dcc5ff9587e643c3a40ee9f" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "2e0e74c59b2761a414d9f48d7bee1e45220b2427" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "96a4713ae041cc85e712bac682cd2e644004d6c6" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "474d6c771d798bca84f0a140b611e36743511e18" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "status": "affected", "versionType": "git", "lessThan": "98d0912e9f841e5529a5b89a972805f34cb1c69d" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.7", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.7" }, { "version": "5.10.259", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.210", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.176", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.143", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.93", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.35", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.0.12", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.0.*" }, { "version": "7.1", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }