{"id":"CVE-2026-43458","state":"PUBLISHED","title":"serial: caif: hold tty->link reference in ldisc_open and ser_release","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: caif: hold tty->link reference in ldisc_open and ser_release\n\nA reproducer triggers a KASAN slab-use-after-free in pty_write_room()\nwhen caif_serial's TX path calls tty_write_room(). The faulting access\nis on tty->link->port.\n\nHold an extra kref on tty->link for the lifetime of the caif_serial line\ndiscipline: get it in ldisc_open() and drop it in ser_release(), and\nalso drop it on the ldisc_open() error path.\n\nWith this change applied, the reproducer no longer triggers the UAF in\nmy testing.","publishedAt":"2026-05-08T14:22:21.997Z","updatedAt":"2026-05-11T22:24:58.635Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"23a3ac2e2262a291498567418227b99e1f3606b1","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"52135420e9f75853ea0c6cea7b736e3e98495f7d","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"ca2ceba983bb23ea0202c2882d963253416654a3","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"8460187b4852fd00bd1c76394358053f3fa4d089","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"27e43356d0defb9fc7fa25265219a3ffeb7b3e98","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"35b58d3bc716ebb9ebd10fe1cac8c1177242511c","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"97a0bb491cae39478c6225381f14e9ac67b7bba7","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"288598d80a068a0e9281de35bcb4ce495f189e2a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/caif/caif_serial.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/caif/caif_serial.c"]}],"references":["https://git.kernel.org/stable/c/23a3ac2e2262a291498567418227b99e1f3606b1","https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d","https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3","https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089","https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98","https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c","https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7","https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43458.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43458","state":"PUBLISHED","datePublished":"2026-05-08T14:22:21.997Z","dateUpdated":"2026-05-11T22:24:58.635Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.010Z"},"containers":{"cna":{"title":"serial: caif: hold tty->link reference in ldisc_open and ser_release","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: caif: hold tty->link reference in ldisc_open and ser_release\n\nA reproducer triggers a KASAN slab-use-after-free in pty_write_room()\nwhen caif_serial's TX path calls tty_write_room(). The faulting access\nis on tty->link->port.\n\nHold an extra kref on tty->link for the lifetime of the caif_serial line\ndiscipline: get it in ldisc_open() and drop it in ser_release(), and\nalso drop it on the ldisc_open() error path.\n\nWith this change applied, the reproducer no longer triggers the UAF in\nmy testing."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"23a3ac2e2262a291498567418227b99e1f3606b1","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"52135420e9f75853ea0c6cea7b736e3e98495f7d","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"ca2ceba983bb23ea0202c2882d963253416654a3","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"8460187b4852fd00bd1c76394358053f3fa4d089","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"27e43356d0defb9fc7fa25265219a3ffeb7b3e98","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"35b58d3bc716ebb9ebd10fe1cac8c1177242511c","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"97a0bb491cae39478c6225381f14e9ac67b7bba7","versionType":"git"},{"version":"e31d5a05948e4478ba8396063d1e1f39880928e2","status":"affected","lessThan":"288598d80a068a0e9281de35bcb4ce495f189e2a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/caif/caif_serial.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/caif/caif_serial.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/23a3ac2e2262a291498567418227b99e1f3606b1"},{"url":"https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d"},{"url":"https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3"},{"url":"https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089"},{"url":"https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98"},{"url":"https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c"},{"url":"https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7"},{"url":"https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:24:58.635Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.18.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}