{"id":"CVE-2022-49264","summary":"exec: Force single empty string when argv is empty","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nexec: Force single empty string when argv is empty\n\nQuoting[1] Ariadne Conill:\n\n\"In several other operating systems, it is a hard requirement that the\nsecond argument to execve(2) be the name of a program, thus prohibiting\na scenario where argc \u003c 1. POSIX 2017 also recommends this behaviour,\nbut it is not an explicit requirement[2]:\n\n    The argument arg0 should point to a filename string that is\n    associated with the process being started by one of the exec\n    functions.\n...\nInterestingly, Michael Kerrisk opened an issue about this in 2008[3],\nbut there was no consensus to support fixing this issue then.\nHopefully now that CVE-2021-4034 shows practical exploitative use[4]\nof this bug in a shellcode, we can reconsider.\n\nThis issue is being tracked in the KSPP issue tracker[5].\"\n\nWhile the initial code searches[6][7] turned up what appeared to be\nmostly corner case tests, trying to that just reject argv == NULL\n(or an immediately terminated pointer list) quickly started tripping[8]\nexisting userspace programs.\n\nThe next best approach is forcing a single empty string into argv and\nadjusting argc to match. The number of programs depending on argc == 0\nseems a smaller set than those calling execve with a NULL argv.\n\nAccount for the additional stack space in bprm_stack_limits(). Inject an\nempty string when argc == 0 (and set argc = 1). Warn about the case so\nuserspace has some notice about the change:\n\n    process './argc0' launched './argc0' with NULL argv: empty string added\n\nAdditionally WARN() and reject NULL argv usage for kernel threads.\n\n[1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org/\n[2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html\n[3] https://bugzilla.kernel.org/show_bug.cgi?id=8408\n[4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt\n[5] https://github.com/KSPP/linux/issues/176\n[6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&literal=0\n[7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%2C%5Cs*NULL&literal=0\n[8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/","modified":"2026-04-02T08:27:26.806805Z","published":"2025-02-26T01:56:14.664Z","related":["SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1194-1","SUSE-SU-2025:1241-1","SUSE-SU-2025:1263-1","SUSE-SU-2025:1293-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49264.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1290eb4412aa0f0e9f3434b406dc8e255da85f9e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1fe82bfd9e4ce93399d815ca458b58505191c3e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/27a6f495b63a1804cc71be45911065db7757a98c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/41f6ea5b9aaa28b740d47ffe995a5013211fdbb0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/98e0c7c702894987732776736c99b85ade6fba45"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8054d3fa5deb84b215d6be1b910a978f3cb840d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b50fb8dbc8b81aaa126387de428f4c42a7c72a73"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cfbfff8ce5e3d674947581f1eb9af0a1b1807950"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dcd46d897adb70d63e025f175a00a89797d31a43"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49264.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-49264"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"},{"fixed":"41f6ea5b9aaa28b740d47ffe995a5013211fdbb0"},{"fixed":"98e0c7c702894987732776736c99b85ade6fba45"},{"fixed":"b50fb8dbc8b81aaa126387de428f4c42a7c72a73"},{"fixed":"1fe82bfd9e4ce93399d815ca458b58505191c3e8"},{"fixed":"27a6f495b63a1804cc71be45911065db7757a98c"},{"fixed":"1290eb4412aa0f0e9f3434b406dc8e255da85f9e"},{"fixed":"a8054d3fa5deb84b215d6be1b910a978f3cb840d"},{"fixed":"cfbfff8ce5e3d674947581f1eb9af0a1b1807950"},{"fixed":"dcd46d897adb70d63e025f175a00a89797d31a43"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49264.json"}}],"schema_version":"1.7.5"}