{"id":"CVE-2024-46844","state":"PUBLISHED","title":"um: line: always fill *error_out in setup_one_line()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\num: line: always fill *error_out in setup_one_line()\n\nThe pointer isn't initialized by callers, but I have\nencountered cases where it's still printed; initialize\nit in all possible cases in setup_one_line().","publishedAt":"2024-09-27T12:39:37.685Z","updatedAt":"2026-08-05T11:38:56.747Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"3bedb7ce080690d0d6172db790790c1219bcbdd5","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"96301fdc2d533a196197c055af875fe33d47ef84","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"c8944d449fda9f58c03bd99649b2df09948fc874","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"43f782c27907f306c664b6614fd6f264ac32cce6","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"289979d64573f43df1d0e6bc6435de63a0d69cdf","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"ec5b47a370177d79ae7773858042c107e21f8ecc","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"fc843d3837ebcb1c16d3768ef3eb55e25d5331f2","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"824ac4a5edd3f7494ab1996826c4f47f8ef0f63d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/um/drivers/line.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.4","versionType":"semver"},{"version":"4.19.322","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.284","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.226","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/um/drivers/line.c"]}],"references":["https://git.kernel.org/stable/c/3bedb7ce080690d0d6172db790790c1219bcbdd5","https://git.kernel.org/stable/c/96301fdc2d533a196197c055af875fe33d47ef84","https://git.kernel.org/stable/c/c8944d449fda9f58c03bd99649b2df09948fc874","https://git.kernel.org/stable/c/43f782c27907f306c664b6614fd6f264ac32cce6","https://git.kernel.org/stable/c/289979d64573f43df1d0e6bc6435de63a0d69cdf","https://git.kernel.org/stable/c/ec5b47a370177d79ae7773858042c107e21f8ecc","https://git.kernel.org/stable/c/fc843d3837ebcb1c16d3768ef3eb55e25d5331f2","https://git.kernel.org/stable/c/824ac4a5edd3f7494ab1996826c4f47f8ef0f63d","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/46xxx/CVE-2024-46844.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-46844","state":"PUBLISHED","datePublished":"2024-09-27T12:39:37.685Z","dateUpdated":"2026-08-05T11:38:56.747Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-09-11T15:12:18.289Z"},"containers":{"cna":{"title":"um: line: always fill *error_out in setup_one_line()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\num: line: always fill *error_out in setup_one_line()\n\nThe pointer isn't initialized by callers, but I have\nencountered cases where it's still printed; initialize\nit in all possible cases in setup_one_line()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"3bedb7ce080690d0d6172db790790c1219bcbdd5","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"96301fdc2d533a196197c055af875fe33d47ef84","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"c8944d449fda9f58c03bd99649b2df09948fc874","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"43f782c27907f306c664b6614fd6f264ac32cce6","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"289979d64573f43df1d0e6bc6435de63a0d69cdf","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"ec5b47a370177d79ae7773858042c107e21f8ecc","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"fc843d3837ebcb1c16d3768ef3eb55e25d5331f2","versionType":"git"},{"version":"31efcebb7d7196adcee73027f513d7c0bf572b47","status":"affected","lessThan":"824ac4a5edd3f7494ab1996826c4f47f8ef0f63d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/um/drivers/line.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.4","versionType":"semver"},{"version":"4.19.322","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.284","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.226","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/um/drivers/line.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3bedb7ce080690d0d6172db790790c1219bcbdd5"},{"url":"https://git.kernel.org/stable/c/96301fdc2d533a196197c055af875fe33d47ef84"},{"url":"https://git.kernel.org/stable/c/c8944d449fda9f58c03bd99649b2df09948fc874"},{"url":"https://git.kernel.org/stable/c/43f782c27907f306c664b6614fd6f264ac32cce6"},{"url":"https://git.kernel.org/stable/c/289979d64573f43df1d0e6bc6435de63a0d69cdf"},{"url":"https://git.kernel.org/stable/c/ec5b47a370177d79ae7773858042c107e21f8ecc"},{"url":"https://git.kernel.org/stable/c/fc843d3837ebcb1c16d3768ef3eb55e25d5331f2"},{"url":"https://git.kernel.org/stable/c/824ac4a5edd3f7494ab1996826c4f47f8ef0f63d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The only ways to reach `setup_one_line()` are the UML kernel command line at boot (`con0=none`/`ssl0=none` via `console_chan_setup`/`ssl_chan_setup`) and the `config`/`remove` commands on the mconsole AF_UNIX datagram socket in `~/.uml/<umid>/mconsole`; no path is driven by received network packets or by an adjacent link peer.\nAC:L - The failure is fully deterministic — two consecutive `remove con0` mconsole commands drive `line->valid` to 0 and then hit the `\"none\"` + `!valid` branch that leaves `*error_out` untouched, with no race, timing window, or memory-layout precondition.\nPR:L - There is no `capable()`, credential, or authentication check anywhere on the `mconsole_remove → con_remove/ssl_remove → line_remove → setup_one_line` path, and the mconsole protocol authenticates nothing; any ordinary local account able to write to the socket (created under a `mkdir(uml_dir, 0777)` tree) can issue the command, and it is not real root or an init-namespace capability.\nUI:N - The fault fires synchronously as a direct consequence of the attacker's own `remove`/`config` command or boot-line setting; no victim has to open a device, mount anything, or take any other action.\nS:U - The oops and the leaked data are confined to the UML kernel instance that owns the vulnerable code; no VM-to-host, IOMMU, or sandbox authority boundary is crossed by the dereference itself.\nC:H - The `stdio_init()`/`ssl_init()` callers pass a genuinely uninitialized stack `char *error` that `setup_one_line()` leaves untouched, and `printk(\"%s\", error)` then dereferences that wild pointer, copying an unbounded NUL-terminated run of UML kernel memory into the kernel log where any unprivileged user can harvest it with `dmesg` — an uncontrolled read of arbitrary kernel memory rather than a small bounded leak.\nI:N - Both the `strlen(NULL)` in `mconsole_reply()` and the `%s` formatting are pure reads; no kernel object is written, freed, or corrupted, and the line state left behind by the failed `remove` is not a security-relevant modification.\nA:H - `mconsole_remove()` passes the still-NULL `err_msg` straight into `mconsole_reply() → strlen(NULL)`, and the boot-time callers dereference a wild stack pointer inside `printk`, either of which produces a kernel oops/SIGSEGV that panics the UML instance."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:38:56.747Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"4.19.322"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"5.4.284"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"5.10.226"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"5.15.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.1.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.6.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.10.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T13:59:13.479006Z","id":"CVE-2024-46844","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T13:59:18.254Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:19:31.529Z"}}]}}}