{"id":"DEBIAN-CVE-2022-49264","details":"In the Linux kernel, the following vulnerability has been resolved:  exec: Force single empty string when argv is empty  Quoting[1] Ariadne Conill:  \"In several other operating systems, it is a hard requirement that the second argument to execve(2) be the name of a program, thus prohibiting a scenario where argc \u003c 1. POSIX 2017 also recommends this behaviour, but it is not an explicit requirement[2]:      The argument arg0 should point to a filename string that is     associated with the process being started by one of the exec     functions. ... Interestingly, Michael Kerrisk opened an issue about this in 2008[3], but there was no consensus to support fixing this issue then. Hopefully now that CVE-2021-4034 shows practical exploitative use[4] of this bug in a shellcode, we can reconsider.  This issue is being tracked in the KSPP issue tracker[5].\"  While the initial code searches[6][7] turned up what appeared to be mostly corner case tests, trying to that just reject argv == NULL (or an immediately terminated pointer list) quickly started tripping[8] existing userspace programs.  The next best approach is forcing a single empty string into argv and adjusting argc to match. The number of programs depending on argc == 0 seems a smaller set than those calling execve with a NULL argv.  Account for the additional stack space in bprm_stack_limits(). Inject an empty string when argc == 0 (and set argc = 1). Warn about the case so userspace has some notice about the change:      process './argc0' launched './argc0' with NULL argv: empty string added  Additionally WARN() and reject NULL argv usage for kernel threads.  [1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org/ [2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html [3] https://bugzilla.kernel.org/show_bug.cgi?id=8408 [4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt [5] https://github.com/KSPP/linux/issues/176 [6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&literal=0 [7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%2C%5Cs*NULL&literal=0 [8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/","modified":"2026-09-01T16:05:30.418022775Z","published":"2025-02-26T07:01:03.337Z","upstream":["CVE-2022-49264"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49264"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49264.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49264.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.17.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49264.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}