{"api_version":"1","generated_at":"2026-06-24T12:16:56+00:00","cve":"CVE-2026-52943","urls":{"html":"https://cve.report/CVE-2026-52943","api":"https://cve.report/api/cve/CVE-2026-52943.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-52943","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-52943"},"summary":{"title":"net: skbuff: fix missing zerocopy reference in pskb_carve helpers","description":"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().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-06-24 10:17:19","updated_at":"2026-06-24 10:17:19"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f","name":"https://git.kernel.org/stable/c/ceafb893b12f23331dcc5ff9587e643c3a40ee9f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578","name":"https://git.kernel.org/stable/c/9b40bdc2a3298225dffab8158208a0d8c6300578","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2e0e74c59b2761a414d9f48d7bee1e45220b2427","name":"https://git.kernel.org/stable/c/2e0e74c59b2761a414d9f48d7bee1e45220b2427","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18","name":"https://git.kernel.org/stable/c/474d6c771d798bca84f0a140b611e36743511e18","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a","name":"https://git.kernel.org/stable/c/fd470f0a97b8e9a125f520265d2f3b088ffb5b8a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37","name":"https://git.kernel.org/stable/c/8dbed691e43a50903658130bde0fcb5abc425b37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6","name":"https://git.kernel.org/stable/c/96a4713ae041cc85e712bac682cd2e644004d6c6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d","name":"https://git.kernel.org/stable/c/98d0912e9f841e5529a5b89a972805f34cb1c69d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-52943","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52943","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 8dbed691e43a50903658130bde0fcb5abc425b37 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 9b40bdc2a3298225dffab8158208a0d8c6300578 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a fd470f0a97b8e9a125f520265d2f3b088ffb5b8a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a ceafb893b12f23331dcc5ff9587e643c3a40ee9f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 2e0e74c59b2761a414d9f48d7bee1e45220b2427 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 96a4713ae041cc85e712bac682cd2e644004d6c6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 474d6c771d798bca84f0a140b611e36743511e18 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fa01ccd883021105e9f8af7d04b9f156fa3494a 98d0912e9f841e5529a5b89a972805f34cb1c69d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.7","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.259 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.210 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.176 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.143 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.93 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.35 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.12 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/core/skbuff.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8dbed691e43a50903658130bde0fcb5abc425b37","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"9b40bdc2a3298225dffab8158208a0d8c6300578","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"fd470f0a97b8e9a125f520265d2f3b088ffb5b8a","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"ceafb893b12f23331dcc5ff9587e643c3a40ee9f","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"2e0e74c59b2761a414d9f48d7bee1e45220b2427","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"96a4713ae041cc85e712bac682cd2e644004d6c6","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"474d6c771d798bca84f0a140b611e36743511e18","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"},{"lessThan":"98d0912e9f841e5529a5b89a972805f34cb1c69d","status":"affected","version":"6fa01ccd883021105e9f8af7d04b9f156fa3494a","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/core/skbuff.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.7"},{"lessThan":"4.7","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.259","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.210","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.176","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.143","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.93","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.35","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.259","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.210","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.176","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.143","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.93","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.35","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.12","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"4.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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()."}],"providerMetadata":{"dateUpdated":"2026-06-24T09:00:12.292Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-52943","datePublished":"2026-06-24T09:00:12.292Z","dateReserved":"2026-06-09T07:44:35.371Z","dateUpdated":"2026-06-24T09:00:12.292Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-24 10:17:19","lastModifiedDate":"2026-06-24 10:17:19","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"52943","Ordinal":"1","Title":"net: skbuff: fix missing zerocopy reference in pskb_carve helper","CVE":"CVE-2026-52943","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"52943","Ordinal":"1","NoteData":"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().","Type":"Description","Title":"net: skbuff: fix missing zerocopy reference in pskb_carve helper"}]}}}