[AutoPR- Security] Patch libssh for CVE-2026-0967, CVE-2026-0966, CVE-2026-0965, CVE-2026-0964 [MEDIUM] (#16410)

Co-authored-by: Aditya Singh <v-aditysing@microsoft.com>

Author: azurelinux-security

SPECS/libssh/CVE-2026-0964.patch

@@ -0,0 +1,44 @@
+From 89fc59935d26f32bbd6d745c2042eb4e888e1b67 Mon Sep 17 00:00:00 2001
+From: Jakub Jelen <jjelen@redhat.com>
+Date: Mon, 22 Dec 2025 19:16:44 +0100
+Subject: [PATCH] CVE-2026-0964 scp: Reject invalid paths received through scp
+
+Signed-off-by: Jakub Jelen <jjelen@redhat.com>
+Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
+(cherry picked from commit daa80818f89347b4d80b0c5b80659f9a9e55e8cc)
+Signed-off-by: Azure Linux Security Servicing Account <azurelinux-security@microsoft.com>
+Upstream-reference: https://git.libssh.org/projects/libssh.git/patch/?id=a5e4b12090b0c939d85af4f29280e40c5b6600aa
+---
+ src/scp.c | 16 ++++++++++++++++
+ 1 file changed, 16 insertions(+)
+
+diff --git a/src/scp.c b/src/scp.c
+index 103822c..c23b7b1 100644
+--- a/src/scp.c
++++ b/src/scp.c
+@@ -848,6 +848,22 @@ int ssh_scp_pull_request(ssh_scp scp)
+         size = strtoull(tmp, NULL, 10);
+         p++;
+         name = strdup(p);
++        /* Catch invalid name:
++         *  - empty ones
++         *  - containing any forward slash -- directory traversal handled
++         *    differently
++         *  - special names "." and ".." referring to the current and parent
++         *    directories -- they are not expected either
++         */
++        if (name == NULL || name[0] == '\0' || strchr(name, '/') ||
++            strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
++            ssh_set_error(scp->session,
++                          SSH_FATAL,
++                          "Received invalid filename: %s",
++                          name == NULL ? "<NULL>" : name);
++            SAFE_FREE(name);
++            goto error;
++        }
+         SAFE_FREE(scp->request_name);
+         scp->request_name = name;
+         if (buffer[0] == 'C') {
+-- 
+2.45.4
+

SPECS/libssh/CVE-2026-0965.patch

@@ -0,0 +1,278 @@
+From 268894dd119cab18560a88dc774baa0129650be9 Mon Sep 17 00:00:00 2001
+From: Azure Linux Security Servicing Account
+ <azurelinux-security@microsoft.com>
+Date: Wed, 1 Apr 2026 19:50:22 +0000
+Subject: [PATCH] Patch CVE-2026-0965 for libssh (applied via patch -p1)
+
+Signed-off-by: Azure Linux Security Servicing Account <azurelinux-security@microsoft.com>
+Upstream-reference: https://git.libssh.org/projects/libssh.git/patch/?id=bf390a042623e02abc8f421c4c5fadc0429a8a76
+---
+ include/libssh/misc.h            |  4 ++
+ include/libssh/priv.h            |  3 ++
+ src/bind_config.c                |  4 +-
+ src/config.c                     |  8 ++--
+ src/dh-gex.c                     |  4 +-
+ src/known_hosts.c                |  2 +-
+ src/knownhosts.c                 |  2 +-
+ src/misc.c                       | 74 ++++++++++++++++++++++++++++++++
+ tests/unittests/torture_config.c | 19 ++++++++
+ 9 files changed, 110 insertions(+), 10 deletions(-)
+
+diff --git a/include/libssh/misc.h b/include/libssh/misc.h
+index 0924ba7..27bdc2d 100644
+--- a/include/libssh/misc.h
++++ b/include/libssh/misc.h
+@@ -21,6 +21,8 @@
+ #ifndef MISC_H_
+ #define MISC_H_
+ 
++#include <stdio.h>
++
+ #ifdef __cplusplus
+ extern "C" {
+ #endif
+@@ -106,6 +108,8 @@ char *ssh_strreplace(const char *src, const char *pattern, const char *repl);
+ 
+ int ssh_check_hostname_syntax(const char *hostname);
+ 
++FILE *ssh_strict_fopen(const char *filename, size_t max_file_size);
++
+ #ifdef __cplusplus
+ }
+ #endif
+diff --git a/include/libssh/priv.h b/include/libssh/priv.h
+index 47af57f..b55df50 100644
+--- a/include/libssh/priv.h
++++ b/include/libssh/priv.h
+@@ -438,6 +438,9 @@ bool is_ssh_initialized(void);
+ #define SSH_ERRNO_MSG_MAX   1024
+ char *ssh_strerror(int err_num, char *buf, size_t buflen);
+ 
++/** The default maximum file size for a configuration file */
++#define SSH_MAX_CONFIG_FILE_SIZE 16 * 1024 * 1024
++
+ #ifdef __cplusplus
+ }
+ #endif
+diff --git a/src/bind_config.c b/src/bind_config.c
+index ed42cbe..c429bce 100644
+--- a/src/bind_config.c
++++ b/src/bind_config.c
+@@ -212,7 +212,7 @@ local_parse_file(ssh_bind bind,
+         return;
+     }
+ 
+-    f = fopen(filename, "r");
++    f = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+     if (f == NULL) {
+         SSH_LOG(SSH_LOG_RARE, "Cannot find file %s to load",
+                 filename);
+@@ -636,7 +636,7 @@ int ssh_bind_config_parse_file(ssh_bind bind, const char *filename)
+      * option to be redefined later by another file. */
+     uint8_t seen[BIND_CFG_MAX] = {0};
+ 
+-    f = fopen(filename, "r");
++    f = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+     if (f == NULL) {
+         return 0;
+     }
+diff --git a/src/config.c b/src/config.c
+index d4d8d41..87cdaaa 100644
+--- a/src/config.c
++++ b/src/config.c
+@@ -215,10 +215,9 @@ local_parse_file(ssh_session session,
+         return;
+     }
+ 
+-    f = fopen(filename, "r");
++    f = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+     if (f == NULL) {
+-        SSH_LOG(SSH_LOG_RARE, "Cannot find file %s to load",
+-                filename);
++        /* The underlying function logs the reasons */
+         return;
+     }
+ 
+@@ -1205,8 +1204,9 @@ int ssh_config_parse_file(ssh_session session, const char *filename)
+     int parsing, rv;
+     bool global = 0;
+ 
+-    f = fopen(filename, "r");
++    f = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+     if (f == NULL) {
++        /* The underlying function logs the reasons */
+         return 0;
+     }
+ 
+diff --git a/src/dh-gex.c b/src/dh-gex.c
+index 642a88a..aadc7c0 100644
+--- a/src/dh-gex.c
++++ b/src/dh-gex.c
+@@ -520,9 +520,9 @@ static int ssh_retrieve_dhgroup(char *moduli_file,
+     }
+ 
+     if (moduli_file != NULL)
+-        moduli = fopen(moduli_file, "r");
++        moduli = ssh_strict_fopen(moduli_file, SSH_MAX_CONFIG_FILE_SIZE);
+     else
+-        moduli = fopen(MODULI_FILE, "r");
++        moduli = ssh_strict_fopen(MODULI_FILE, SSH_MAX_CONFIG_FILE_SIZE);
+ 
+     if (moduli == NULL) {
+         char err_msg[SSH_ERRNO_MSG_MAX] = {0};
+diff --git a/src/known_hosts.c b/src/known_hosts.c
+index f660a6f..ba2ae4d 100644
+--- a/src/known_hosts.c
++++ b/src/known_hosts.c
+@@ -83,7 +83,7 @@ static struct ssh_tokens_st *ssh_get_knownhost_line(FILE **file,
+     struct ssh_tokens_st *tokens = NULL;
+ 
+     if (*file == NULL) {
+-        *file = fopen(filename,"r");
++        *file = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+         if (*file == NULL) {
+             return NULL;
+         }
+diff --git a/src/knownhosts.c b/src/knownhosts.c
+index 109b4f0..f0fde69 100644
+--- a/src/knownhosts.c
++++ b/src/knownhosts.c
+@@ -232,7 +232,7 @@ static int ssh_known_hosts_read_entries(const char *match,
+     FILE *fp = NULL;
+     int rc;
+ 
+-    fp = fopen(filename, "r");
++    fp = ssh_strict_fopen(filename, SSH_MAX_CONFIG_FILE_SIZE);
+     if (fp == NULL) {
+         char err_msg[SSH_ERRNO_MSG_MAX] = {0};
+         SSH_LOG(SSH_LOG_WARN, "Failed to open the known_hosts file '%s': %s",
+diff --git a/src/misc.c b/src/misc.c
+index f371f33..d936385 100644
+--- a/src/misc.c
++++ b/src/misc.c
+@@ -37,6 +37,7 @@
+ #endif /* _WIN32 */
+ 
+ #include <errno.h>
++#include <fcntl.h>
+ #include <limits.h>
+ #include <stdio.h>
+ #include <string.h>
+@@ -2074,4 +2075,77 @@ int ssh_check_hostname_syntax(const char *hostname)
+     return SSH_OK;
+ }
+ 
++/**
++ * @internal
++ *
++ * @brief Safely open a file containing some configuration.
++ *
++ * Runs checks if the file can be used as some configuration file (is regular
++ * file and is not too large). If so, returns the opened file (for reading).
++ * Otherwise logs error and returns `NULL`.
++ *
++ * @param filename      The path to the file to open.
++ * @param max_file_size Maximum file size that is accepted.
++ *
++ * @returns the opened file or `NULL` on error.
++ */
++FILE *ssh_strict_fopen(const char *filename, size_t max_file_size)
++{
++    FILE *f = NULL;
++    struct stat sb;
++    char err_msg[SSH_ERRNO_MSG_MAX] = {0};
++    int r, fd;
++
++    /* open first to avoid TOCTOU */
++    fd = open(filename, O_RDONLY);
++    if (fd == -1) {
++        SSH_LOG(SSH_LOG_RARE,
++                "Failed to open a file %s for reading: %s",
++                filename,
++                ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
++        return NULL;
++    }
++
++    /* Check the file is sensible for a configuration file */
++    r = fstat(fd, &sb);
++    if (r != 0) {
++        SSH_LOG(SSH_LOG_RARE,
++                "Failed to stat %s: %s",
++                filename,
++                ssh_strerror(errno, err_msg, SSH_ERRNO_MSG_MAX));
++        close(fd);
++        return NULL;
++    }
++    if ((sb.st_mode & S_IFMT) != S_IFREG) {
++        SSH_LOG(SSH_LOG_RARE,
++                "The file %s is not a regular file: skipping",
++                filename);
++        close(fd);
++        return NULL;
++    }
++
++    if ((size_t)sb.st_size > max_file_size) {
++        SSH_LOG(SSH_LOG_RARE,
++                "The file %s is too large (%jd MB > %zu MB): skipping",
++                filename,
++                (intmax_t)sb.st_size / 1024 / 1024,
++                max_file_size / 1024 / 1024);
++        close(fd);
++        return NULL;
++    }
++
++    f = fdopen(fd, "r");
++    if (f == NULL) {
++        SSH_LOG(SSH_LOG_RARE,
++                "Failed to open a file %s for reading: %s",
++                filename,
++                ssh_strerror(r, err_msg, SSH_ERRNO_MSG_MAX));
++        close(fd);
++        return NULL;
++    }
++
++    /* the flcose() will close also the underlying fd */
++    return f;
++}
++
+ /** @} */
+diff --git a/tests/unittests/torture_config.c b/tests/unittests/torture_config.c
+index b7c763a..b218f9e 100644
+--- a/tests/unittests/torture_config.c
++++ b/tests/unittests/torture_config.c
+@@ -1850,6 +1850,22 @@ static void torture_config_make_absolute_no_sshdir(void **state)
+     torture_config_make_absolute_int(state, 1);
+ }
+ 
++/* Invalid configuration files */
++static void torture_config_invalid(void **state)
++{
++    ssh_session session = *state;
++
++    ssh_options_set(session, SSH_OPTIONS_HOST, "Bar");
++
++    /* non-regular file -- ignored (or missing on non-unix) so OK */
++    _parse_config(session, "/dev/random", NULL, SSH_OK);
++
++#ifndef _WIN32
++    /* huge file -- ignored (or missing on non-unix) so OK */
++    _parse_config(session, "/proc/kcore", NULL, SSH_OK);
++#endif
++}
++
+ int torture_run_tests(void)
+ {
+     int rc;
+@@ -1922,6 +1938,9 @@ int torture_run_tests(void)
+                                         setup, teardown),
+         cmocka_unit_test_setup_teardown(torture_config_make_absolute_no_sshdir,
+                                         setup_no_sshdir, teardown),
++        cmocka_unit_test_setup_teardown(torture_config_invalid,
++                                        setup,
++                                        teardown),
+     };
+
+
+-- 
+2.45.4
+

SPECS/libssh/CVE-2026-0966.patch

@@ -0,0 +1,34 @@
+From 1fd7f07af7dc69d4b86dabde62dc5ecbf449cfd7 Mon Sep 17 00:00:00 2001
+From: Jakub Jelen <jjelen@redhat.com>
+Date: Thu, 8 Jan 2026 12:09:50 +0100
+Subject: [PATCH] CVE-2026-0966 misc: Avoid heap buffer underflow in
+ ssh_get_hexa
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Signed-off-by: Jakub Jelen <jjelen@redhat.com>
+Reviewed-by: Pavol Žáčik <pzacik@redhat.com>
+(cherry picked from commit 417a095e6749a1f3635e02332061edad3c6a3401)
+Signed-off-by: Azure Linux Security Servicing Account <azurelinux-security@microsoft.com>
+Upstream-reference: https://git.libssh.org/projects/libssh.git/patch/?id=6ba5ff1b7b1547a59f750fbc06b89737b7456117
+---
+ src/misc.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/misc.c b/src/misc.c
+index d936385..e78c92b 100644
+--- a/src/misc.c
++++ b/src/misc.c
+@@ -452,7 +452,7 @@ char *ssh_get_hexa(const unsigned char *what, size_t len)
+     size_t i;
+     size_t hlen = len * 3;
+ 
+-    if (len > (UINT_MAX - 1) / 3) {
++    if (what == NULL || len < 1 || len > (UINT_MAX - 1) / 3) {
+         return NULL;
+     }
+ 
+-- 
+2.45.4
+