openssh: fix CVE-2024-6387

sshd(8) in Portable OpenSSH versions 8.5p1 to 9.7p1 (inclusive).
Race condition resulting in potential remote code execution.
A race condition in sshd(8) could allow remote code execution as root on non-OpenBSD systems.
This attack could be prevented by disabling the login grace timeout (LoginGraceTime=0 in sshd_config)
though this makes denial-of service against sshd(8) considerably easier.
For more information, please refer to the release notes [1] and the
report from the Qualys Security Advisory Team [2] who discovered the bug.

[1] https://www.openssh.com/txt/release-9.8
[2] https://www.qualys.com/2024/07/01/cve-2024-6387/regresshion.txt

References:
https://www.openssh.com/security.html

(From OE-Core rev: 7ba7c96f31bd81c5d1352136e405e99c3df29ea7)

Signed-off-by: Jose Quaresma <jose.quaresma@foundries.io>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 28 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/openssh/openssh/CVE-2024-6387.patch b/meta/recipes-connectivity/openssh/openssh/CVE-2024-6387.patch
new file mode 100644
index 0000000000..3e7c707100
--- /dev/null
+++ b/meta/recipes-connectivity/openssh/openssh/CVE-2024-6387.patch
@@ -0,0 +1,27 @@
+Description: fix signal handler race condition
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/2070497
+
+CVE: CVE-2024-6387
+
+Upstream-Status: Backport
+https://git.launchpad.net/ubuntu/+source/openssh/commit/?h=applied/ubuntu/jammy-devel&id=b059bcfa928df4ff2d103ae2e8f4e3136ee03efc
+
+Signed-off-by: Jose Quaresma <jose.quaresma@foundries.io>
+
+--- a/log.c
++++ b/log.c
+@@ -452,12 +452,14 @@ void
+ sshsigdie(const char *file, const char *func, int line, int showfunc,
+     LogLevel level, const char *suffix, const char *fmt, ...)
+ {
++#if 0
+        va_list args;
+ 
+        va_start(args, fmt);
+        sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_FATAL,
+            suffix, fmt, args);
+        va_end(args);
++#endif
+        _exit(1);
+ }
+ 
diff --git a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
index 0bc14c5553..69eade3ee7 100644
--- a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
+++ b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
@@ -26,6 +26,7 @@ SRC_URI = "http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-${PV}.tar
            file://sshd_check_keys \
            file://0001-regress-banner.sh-log-input-and-output-files-on-erro.patch \
            file://0001-systemd-Add-optional-support-for-systemd-sd_notify.patch \
+           file://CVE-2024-6387.patch \
            "
 SRC_URI[sha256sum] = "490426f766d82a2763fcacd8d83ea3d70798750c7bd2aff2e57dc5660f773ffd"