{ "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-2026-43050", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-43050", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-05-01T14:15:44.542Z", "updatedAt": "2026-05-11T22:16:44.767Z", "importedAt": "2026-10-24T01:58:08.712Z", "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": "atm: lec: fix use-after-free in sock_def_readable()", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\natm: lec: fix use-after-free in sock_def_readable()\n\nA race condition exists between lec_atm_close() setting priv->lecd\nto NULL and concurrent access to priv->lecd in send_to_lecd(),\nlec_handle_bridge(), and lec_atm_send(). When the socket is freed\nvia RCU while another thread is still using it, a use-after-free\noccurs in sock_def_readable() when accessing the socket's wait queue.\n\nThe root cause is that lec_atm_close() clears priv->lecd without\nany synchronization, while callers dereference priv->lecd without\nany protection against concurrent teardown.\n\nFix this by converting priv->lecd to an RCU-protected pointer:\n- Mark priv->lecd as __rcu in lec.h\n- Use rcu_assign_pointer() in lec_atm_close() and lecd_attach()\n for safe pointer assignment\n- Use rcu_access_pointer() for NULL checks that do not dereference\n the pointer in lec_start_xmit(), lec_push(), send_to_lecd() and\n lecd_attach()\n- Use rcu_read_lock/rcu_dereference/rcu_read_unlock in send_to_lecd(),\n lec_handle_bridge() and lec_atm_send() to safely access lecd\n- Use rcu_assign_pointer() followed by synchronize_rcu() in\n lec_atm_close() to ensure all readers have completed before\n proceeding. This is safe since lec_atm_close() is called from\n vcc_release() which holds lock_sock(), a sleeping lock.\n- Remove the manual sk_receive_queue drain from lec_atm_close()\n since vcc_destroy_socket() already drains it after lec_atm_close()\n returns.\n\nv2: Switch from spinlock + sock_hold/put approach to RCU to properly\n fix the race. The v1 spinlock approach had two issues pointed out\n by Eric Dumazet:\n 1. priv->lecd was still accessed directly after releasing the\n lock instead of using a local copy.\n 2. The spinlock did not prevent packets being queued after\n lec_atm_close() drains sk_receive_queue since timer and\n workqueue paths bypass netif_stop_queue().\n\nNote: Syzbot patch testing was attempted but the test VM terminated\n unexpectedly with \"Connection to localhost closed by remote host\",\n likely due to a QEMU AHCI emulation issue unrelated to this fix.\n Compile testing with \"make W=1 net/atm/lec.o\" passes cleanly.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "3e8b25f32f2f35549d03d77da030a24a45bdef5b" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "750a33f417f3d196b86375f8d9f8938bacf130fe" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "317843d5355062020649124eb4a0d7acbcc3f53e" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "b256d055da47258e63f8b40965f276c5f23d229a" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "3989740fa4978e1d2d51ecc62be1b01093e104ad" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "abc10f85a3965ac14b9ed7ad3e67b35604a63aa3" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "5fbbb1ff936d7ff9528d929c1549977e8123d8a8" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "status": "affected", "versionType": "git", "lessThan": "922814879542c2e397b0e9641fd36b8202a8e555" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "2.6.12" }, { "version": "5.10.253", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.203", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.168", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.134", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.81", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.22", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "6.19.12", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.19.*" }, { "version": "7.0", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }