From: Vijay Anusuri <[email protected]> Pick patch according to [1]
[1] https://security-tracker.debian.org/tracker/CVE-2026-72693 [2] https://nvd.nist.gov/vuln/detail/CVE-2026-72693 [3] https://access.redhat.com/security/cve/cve-2026-72693 Signed-off-by: Vijay Anusuri <[email protected]> Signed-off-by: Yoann Congal <[email protected]> --- .../recipes-core/kbd/kbd/CVE-2026-72693.patch | 155 ++++++++++++++++++ meta/recipes-core/kbd/kbd_2.6.4.bb | 1 + 2 files changed, 156 insertions(+) create mode 100644 meta/recipes-core/kbd/kbd/CVE-2026-72693.patch diff --git a/meta/recipes-core/kbd/kbd/CVE-2026-72693.patch b/meta/recipes-core/kbd/kbd/CVE-2026-72693.patch new file mode 100644 index 00000000000..71cef126a6e --- /dev/null +++ b/meta/recipes-core/kbd/kbd/CVE-2026-72693.patch @@ -0,0 +1,155 @@ +From 78d5ae119742e87baa7dbe0f5c4107e7533fd698 Mon Sep 17 00:00:00 2001 +From: Alexey Gladkov <[email protected]> +Date: Tue, 12 May 2026 10:20:50 +0200 +Subject: [PATCH] openvt: make -u process matching more conservative + +The -u mode relies on the current VT owner to decide which user should +be used for the new login session. Make that check stricter by requiring +a matching process owner and controlling terminal instead of relying on +the ownership of an inherited file descriptor. + +Also reject root as a pre-authenticated target and document the tighter +behavior in the man page. + +Signed-off-by: Alexey Gladkov <[email protected]> + +Upstream-Status: Backport [https://github.com/legionus/kbd/commit/78d5ae119742e87baa7dbe0f5c4107e7533fd698] +CVE: CVE-2026-72693 +Signed-off-by: Vijay Anusuri <[email protected]> +--- + docs/man/man1/openvt.1 | 10 +++++++ + src/openvt.c | 64 +++++++++++++++++++++++++++++++++++++----- + 2 files changed, 67 insertions(+), 7 deletions(-) + +diff --git a/docs/man/man1/openvt.1 b/docs/man/man1/openvt.1 +index 79bfe3f..074de96 100644 +--- a/docs/man/man1/openvt.1 ++++ b/docs/man/man1/openvt.1 +@@ -36,6 +36,8 @@ will be made the new current VT. + .I "\-u, \-\-user" + Figure out the owner of the current VT, and run login as that user. + Suitable to be called by init. Shouldn't be used with \fI\-c\fR or \fI\-l\fR. ++This option refuses to pre-authenticate root and requires a process owned by ++the VT owner whose controlling terminal is the current VT. + .TP + .I "\-l, \-\-login" + Make the command a login shell. A \- is prepended to the name of the command +@@ -64,6 +66,14 @@ If + is compiled with a getopt_long() and you wish to set + options to the command to be run, then you must supply + the end of options \-\- flag before the command. ++.PP ++The ++.B \-u ++option uses ++.BR "login -f" ++and therefore bypasses normal password authentication for the detected user. ++It is intended only for controlled init or keyboard-request configurations. ++Use a normal authenticated login command when authentication is required. + .SH EXAMPLES + .B openvt + can be used to start a shell on the next free VT, by using the command: +diff --git a/src/openvt.c b/src/openvt.c +index 5980361..b8436fe 100644 +--- a/src/openvt.c ++++ b/src/openvt.c +@@ -78,6 +78,51 @@ usage(int rc, const struct kbd_help *options) + exit(rc); + } + ++static int ++proc_pid_stat(const char *pid, uid_t *uid, dev_t *tty) ++{ ++ char filename[NAME_MAX + 12]; ++ char line[BUFSIZ]; ++ char *lp, *rp; ++ FILE *fp; ++ struct stat st; ++ long tty_nr; ++ ++ snprintf(filename, sizeof(filename), "/proc/%s/stat", pid); ++ fp = fopen(filename, "r"); ++ if (!fp) ++ return -1; ++ ++ if (fstat(fileno(fp), &st)) { ++ fclose(fp); ++ return -1; ++ } ++ ++ if (!fgets(line, sizeof(line), fp)) { ++ fclose(fp); ++ return -1; ++ } ++ fclose(fp); ++ ++ rp = strrchr(line, ')'); ++ if (!rp) ++ return -1; ++ ++ /* ++ * /proc/<pid>/stat fields after comm are: ++ * state ppid pgrp session tty_nr ... ++ */ ++ if (!rp || sscanf(rp + 1, " %*c %*d %*d %*d %ld", &tty_nr) != 1) ++ return -1; ++ ++ if (tty_nr <= 0) ++ return -1; ++ ++ *uid = st.st_uid; ++ *tty = (dev_t) tty_nr; ++ return 0; ++} ++ + /* + * Support for Spawn_Console: openvt running from init + * added by Joshua Spoerri, Thu Jul 18 21:13:16 EDT 1996 +@@ -109,8 +154,7 @@ authenticate_user(int curvt) + DIR *dp; + struct dirent *dentp; + struct stat buf; +- dev_t console_dev; +- ino_t console_ino; ++ dev_t console_rdev; + uid_t console_uid; + char filename[NAME_MAX + 12]; + struct passwd *pwnam; +@@ -130,10 +174,12 @@ authenticate_user(int curvt) + kbd_error(EXIT_FAILURE, errsv, "%s", filename); + } + } +- console_dev = buf.st_dev; +- console_ino = buf.st_ino; ++ console_rdev = buf.st_rdev; + console_uid = buf.st_uid; + ++ if (console_uid == 0) ++ kbd_error(EXIT_FAILURE, 0, _("Refusing to pre-authenticate root on current tty.")); ++ + /* get the owner of current tty */ + if (!(pwnam = getpwuid(console_uid))) + kbd_error(EXIT_FAILURE, errno, "getpwuid"); +@@ -141,12 +187,16 @@ authenticate_user(int curvt) + /* check to make sure that user has a process on that tty */ + /* this will fail for example when X is running on the tty */ + while ((dentp = readdir(dp))) { +- sprintf(filename, "/proc/%s/fd/0", dentp->d_name); ++ uid_t proc_uid; ++ dev_t proc_tty; ++ ++ if (dentp->d_name[0] < '0' || dentp->d_name[0] > '9') ++ continue; + +- if (stat(filename, &buf)) ++ if (proc_pid_stat(dentp->d_name, &proc_uid, &proc_tty) < 0) + continue; + +- if (buf.st_dev == console_dev && buf.st_ino == console_ino && buf.st_uid == console_uid) ++ if (proc_uid == console_uid && proc_tty == console_rdev) + goto got_a_process; + } + +-- +2.43.0 + diff --git a/meta/recipes-core/kbd/kbd_2.6.4.bb b/meta/recipes-core/kbd/kbd_2.6.4.bb index 2331b51e595..489218a4029 100644 --- a/meta/recipes-core/kbd/kbd_2.6.4.bb +++ b/meta/recipes-core/kbd/kbd_2.6.4.bb @@ -25,6 +25,7 @@ RCONFLICTS:${PN} = "console-tools" SRC_URI = "${KERNELORG_MIRROR}/linux/utils/${BPN}/${BP}.tar.xz \ file://0001-Remove-non-free-Agafari-fonts.patch \ + file://CVE-2026-72693.patch \ " SRC_URI[sha256sum] = "519f8d087aecca7e0a33cd084bef92c066eb19731666653dcc70c9d71aa40926"
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