{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52943","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.371Z","datePublished":"2026-06-24T09:00:12.292Z","dateUpdated":"2026-07-07T12:05:03.334Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-28T06:37:01.760Z"},"descriptions":[{"lang":"en","value":"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()."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"],"versions":[{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"8dbed691e43a50903658130bde0fcb5abc425b37","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"9b40bdc2a3298225dffab8158208a0d8c6300578","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"fd470f0a97b8e9a125f520265d2f3b088ffb5b8a","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"ceafb893b12f23331dcc5ff9587e643c3a40ee9f","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"2e0e74c59b2761a414d9f48d7bee1e45220b2427","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"96a4713ae041cc85e712bac682cd2e644004d6c6","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"474d6c771d798bca84f0a140b611e36743511e18","status":"affected","versionType":"git"},{"version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","lessThan":"98d0912e9f841e5529a5b89a972805f34cb1c69d","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"],"versions":[{"version":"4.7","status":"affected"},{"version":"0","lessThan":"4.7","status":"unaffected","versionType":"semver"},{"version":"5.10.259","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.210","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.176","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.143","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.93","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.35","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.12","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"4.7","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37"},{"url":"https://git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578"},{"url":"https://git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a"},{"url":"https://git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f"},{"url":"https://git.kernel.org/stable/c/2e0e74c59b2761a414d9f48d7bee1e45220b2427"},{"url":"https://git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6"},{"url":"https://git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18"},{"url":"https://git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d"}],"title":"net: skbuff: fix missing zerocopy reference in pskb_carve helpers","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"cpes":["cpe:/o:redhat:enterprise_linux:10"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 10","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:6"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 6","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat"}],"datePublic":"2026-06-24T00:00:00.000Z","descriptions":[{"lang":"en","value":"A flaw was found in the Linux kernel. The `pskb_carve_inside_header()` and `pskb_carve_inside_nonlinear()` helper functions, which handle network packet buffers, do not correctly account for zero-copy references. This oversight can lead to a use-after-free vulnerability, where memory is prematurely released while still in use. A local unprivileged user can exploit this flaw to achieve full root privilege escalation on the system."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-911","description":"Improper Update of Reference Count","lang":"en","type":"CWE"}]}],"references":[{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-52943"},{"name":"RHBZ#2492137","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492137"},{"tags":["x_sadp-csaf-vex"],"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52943.json"}],"timeline":[{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Made public."}],"title":"kernel: net: skbuff: fix missing zerocopy reference in pskb_carve helpers","x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"},"providerMetadata":{"orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","shortName":"redhat-SADP","dateUpdated":"2026-07-07T12:05:03.334Z"}}]}}