{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23472","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-01-13T15:37:46.022Z","datePublished":"2026-04-03T15:15:51.209Z","dateUpdated":"2026-05-11T22:07:41.736Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:07:41.736Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN\n\nuart_write_room() and uart_write() behave inconsistently when\nxmit_buf is NULL (which happens for PORT_UNKNOWN ports that were\nnever properly initialized):\n\n- uart_write_room() returns kfifo_avail() which can be > 0\n- uart_write() checks xmit_buf and returns 0 if NULL\n\nThis inconsistency causes an infinite loop in drivers that rely on\ntty_write_room() to determine if they can write:\n\n  while (tty_write_room(tty) > 0) {\n      written = tty->ops->write(...);\n      // written is always 0, loop never exits\n  }\n\nFor example, caif_serial's handle_tx() enters an infinite loop when\nused with PORT_UNKNOWN serial ports, causing system hangs.\n\nFix by making uart_write_room() also check xmit_buf and return 0 if\nit's NULL, consistent with uart_write().\n\nReproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13"}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"],"versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"efe85a557186b7fe915572ae93a8f3f78bfd9a22","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"bc70f2b36cf474d5cc8ecbcaf57f3e326fdec67c","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"455ce986fa356ff43a43c0d363ba95fa152f21d5","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"],"versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"6.18.20","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.10","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","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":"2.6.12","versionEndExcluding":"6.18.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.19.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/efe85a557186b7fe915572ae93a8f3f78bfd9a22"},{"url":"https://git.kernel.org/stable/c/bc70f2b36cf474d5cc8ecbcaf57f3e326fdec67c"},{"url":"https://git.kernel.org/stable/c/455ce986fa356ff43a43c0d363ba95fa152f21d5"}],"title":"serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN","x_generator":{"engine":"bippy-1.2.0"}}}}