{"id":"CVE-2024-26998","state":"PUBLISHED","title":"serial: core: Clearing the circular buffer before NULLifying it","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: Clearing the circular buffer before NULLifying it\n\nThe circular buffer is NULLified in uart_tty_port_shutdown()\nunder the spin lock. However, the PM or other timer based callbacks\nmay still trigger after this event without knowning that buffer pointer\nis not valid. Since the serial code is a bit inconsistent in checking\nthe buffer state (some rely on the head-tail positions, some on the\nbuffer pointer), it's better to have both aligned, i.e. buffer pointer\nto be NULL and head-tail possitions to be the same, meaning it's empty.\nThis will prevent asynchronous calls to dereference NULL pointer as\nreported recently in 8250 case:\n\n  BUG: kernel NULL pointer dereference, address: 00000cf5\n  Workqueue: pm pm_runtime_work\n  EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809)\n  ...\n  ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809)\n  __start_tx (drivers/tty/serial/8250/8250_port.c:1551)\n  serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654)\n  serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63)\n  __rpm_callback (drivers/base/power/runtime.c:393)\n  ? serial_port_remove (drivers/tty/serial/serial_port.c:50)\n  rpm_suspend (drivers/base/power/runtime.c:447)\n\nThe proposed change will prevent ->start_tx() to be called during\nsuspend on shut down port.","publishedAt":"2024-05-01T05:28:25.905Z","updatedAt":"2026-05-23T15:41:02.315Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"434beb66368d4fb4d3119c2116b9398500adbf47","status":"affected","lessThan":"7ae7104d54342433a3a73975f6569beefdd86350","versionType":"git"},{"version":"43066e32227ecde674e8ae1fcdd4a1ede67680c2","status":"affected","lessThan":"bb1118905e875c111d7ccef9aee86ac5e4e7f985","versionType":"git"},{"version":"43066e32227ecde674e8ae1fcdd4a1ede67680c2","status":"affected","lessThan":"9cf7ea2eeb745213dc2a04103e426b960e807940","versionType":"git"},{"version":"a629a9b2f7699314a4abe8fbc37b0ee667b60f33","status":"affected","versionType":"git"},{"version":"6.6.24","status":"affected","lessThan":"6.6.29","versionType":"semver"},{"version":"6.7.12","status":"affected","lessThan":"6.8","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.29","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.8.8","status":"unaffected","lessThanOrEqual":"6.8.*","versionType":"semver"},{"version":"6.9","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"]}],"references":["https://git.kernel.org/stable/c/7ae7104d54342433a3a73975f6569beefdd86350","https://git.kernel.org/stable/c/bb1118905e875c111d7ccef9aee86ac5e4e7f985","https://git.kernel.org/stable/c/9cf7ea2eeb745213dc2a04103e426b960e807940","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY/","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53/","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW/"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:10.607Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/26xxx/CVE-2024-26998.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-26998","state":"PUBLISHED","datePublished":"2024-05-01T05:28:25.905Z","dateUpdated":"2026-05-23T15:41:02.315Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-19T14:20:24.206Z"},"containers":{"cna":{"title":"serial: core: Clearing the circular buffer before NULLifying it","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: Clearing the circular buffer before NULLifying it\n\nThe circular buffer is NULLified in uart_tty_port_shutdown()\nunder the spin lock. However, the PM or other timer based callbacks\nmay still trigger after this event without knowning that buffer pointer\nis not valid. Since the serial code is a bit inconsistent in checking\nthe buffer state (some rely on the head-tail positions, some on the\nbuffer pointer), it's better to have both aligned, i.e. buffer pointer\nto be NULL and head-tail possitions to be the same, meaning it's empty.\nThis will prevent asynchronous calls to dereference NULL pointer as\nreported recently in 8250 case:\n\n  BUG: kernel NULL pointer dereference, address: 00000cf5\n  Workqueue: pm pm_runtime_work\n  EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809)\n  ...\n  ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809)\n  __start_tx (drivers/tty/serial/8250/8250_port.c:1551)\n  serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654)\n  serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63)\n  __rpm_callback (drivers/base/power/runtime.c:393)\n  ? serial_port_remove (drivers/tty/serial/serial_port.c:50)\n  rpm_suspend (drivers/base/power/runtime.c:447)\n\nThe proposed change will prevent ->start_tx() to be called during\nsuspend on shut down port."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"434beb66368d4fb4d3119c2116b9398500adbf47","status":"affected","lessThan":"7ae7104d54342433a3a73975f6569beefdd86350","versionType":"git"},{"version":"43066e32227ecde674e8ae1fcdd4a1ede67680c2","status":"affected","lessThan":"bb1118905e875c111d7ccef9aee86ac5e4e7f985","versionType":"git"},{"version":"43066e32227ecde674e8ae1fcdd4a1ede67680c2","status":"affected","lessThan":"9cf7ea2eeb745213dc2a04103e426b960e807940","versionType":"git"},{"version":"a629a9b2f7699314a4abe8fbc37b0ee667b60f33","status":"affected","versionType":"git"},{"version":"6.6.24","status":"affected","lessThan":"6.6.29","versionType":"semver"},{"version":"6.7.12","status":"affected","lessThan":"6.8","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.8","versionType":"semver"},{"version":"6.6.29","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.8.8","status":"unaffected","lessThanOrEqual":"6.8.*","versionType":"semver"},{"version":"6.9","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/serial_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7ae7104d54342433a3a73975f6569beefdd86350"},{"url":"https://git.kernel.org/stable/c/bb1118905e875c111d7ccef9aee86ac5e4e7f985"},{"url":"https://git.kernel.org/stable/c/9cf7ea2eeb745213dc2a04103e426b960e807940"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T15:41:02.315Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.24","versionEndExcluding":"6.6.29"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.8.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7.12"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-26998","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-05-09T18:39:13.227309Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-07-05T17:22:46.551Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/7ae7104d54342433a3a73975f6569beefdd86350","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/bb1118905e875c111d7ccef9aee86ac5e4e7f985","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9cf7ea2eeb745213dc2a04103e426b960e807940","tags":["x_transferred"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY/"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53/"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW/"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-04T17:16:05.094Z"}}]}}}