curl: CVE-2023-27534 SFTP path resolving discrepancy

Upstream-Status: Backport from https://github.com/curl/curl/commit/4e2b52b5f7a3bf50a0f1494155717b02cc1df6d6

(From OE-Core rev: 7919a5a5eaa2689db9f0e8110b923bbfe0a610ab)

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 123 insertions, 0 deletions

diff --git a/meta/recipes-support/curl/curl/CVE-2023-27534.patch b/meta/recipes-support/curl/curl/CVE-2023-27534.patch
new file mode 100644
index 0000000000..9109faaf88
--- /dev/null
+++ b/meta/recipes-support/curl/curl/CVE-2023-27534.patch
@@ -0,0 +1,122 @@
+From 4e2b52b5f7a3bf50a0f1494155717b02cc1df6d6 Mon Sep 17 00:00:00 2001
+From: Daniel Stenberg <daniel@haxx.se>
+Date: Thu, 9 Mar 2023 16:22:11 +0100
+Subject: [PATCH] curl_path: create the new path with dynbuf
+
+CVE: CVE-2023-27534
+Upstream-Status: Backport [https://github.com/curl/curl/commit/4e2b52b5f7a3bf50a0f1494155717b02cc1df6d6]
+
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
+---
+ lib/curl_path.c | 71 ++++++++++++++++++++++++-------------------------
+ 1 file changed, 35 insertions(+), 36 deletions(-)
+
+diff --git a/lib/curl_path.c b/lib/curl_path.c
+index a1669d1..b9c470f 100644
+--- a/lib/curl_path.c
++++ b/lib/curl_path.c
+@@ -30,66 +30,65 @@
+ #include "escape.h"
+ #include "memdebug.h"
+ 
++#define MAX_SSHPATH_LEN 100000 /* arbitrary */
++
+ /* figure out the path to work with in this particular request */
+ CURLcode Curl_getworkingpath(struct Curl_easy *data,
+                              char *homedir,  /* when SFTP is used */
+                              char **path) /* returns the  allocated
+                                              real path to work with */
+ {
+-  char *real_path = NULL;
+   char *working_path;
+   size_t working_path_len;
++  struct dynbuf npath;
+   CURLcode result =
+     Curl_urldecode(data->state.up.path, 0, &working_path,
+                    &working_path_len, REJECT_ZERO);
+   if(result)
+     return result;
+ 
++  /* new path to switch to in case we need to */
++  Curl_dyn_init(&npath, MAX_SSHPATH_LEN);
++
+   /* Check for /~/, indicating relative to the user's home directory */
+-  if(data->conn->handler->protocol & CURLPROTO_SCP) {
+-    real_path = malloc(working_path_len + 1);
+-    if(!real_path) {
++  if((data->conn->handler->protocol & CURLPROTO_SCP) &&
++     (working_path_len > 3) && (!memcmp(working_path, "/~/", 3))) {
++    /* It is referenced to the home directory, so strip the leading '/~/' */
++    if(Curl_dyn_addn(&npath, &working_path[3], working_path_len - 3)) {
+       free(working_path);
+       return CURLE_OUT_OF_MEMORY;
+     }
+-    if((working_path_len > 3) && (!memcmp(working_path, "/~/", 3)))
+-      /* It is referenced to the home directory, so strip the leading '/~/' */
+-      memcpy(real_path, working_path + 3, working_path_len - 2);
+-    else
+-      memcpy(real_path, working_path, 1 + working_path_len);
+   }
+-  else if(data->conn->handler->protocol & CURLPROTO_SFTP) {
+-    if((working_path_len > 1) && (working_path[1] == '~')) {
+-      size_t homelen = strlen(homedir);
+-      real_path = malloc(homelen + working_path_len + 1);
+-      if(!real_path) {
+-        free(working_path);
+-        return CURLE_OUT_OF_MEMORY;
+-      }
+-      /* It is referenced to the home directory, so strip the
+-         leading '/' */
+-      memcpy(real_path, homedir, homelen);
+-      real_path[homelen] = '/';
+-      real_path[homelen + 1] = '\0';
+-      if(working_path_len > 3) {
+-        memcpy(real_path + homelen + 1, working_path + 3,
+-               1 + working_path_len -3);
+-      }
++  else if((data->conn->handler->protocol & CURLPROTO_SFTP) &&
++          (working_path_len > 2) && !memcmp(working_path, "/~/", 3)) {
++    size_t len;
++    const char *p;
++    int copyfrom = 3;
++    if(Curl_dyn_add(&npath, homedir)) {
++      free(working_path);
++      return CURLE_OUT_OF_MEMORY;
+     }
+-    else {
+-      real_path = malloc(working_path_len + 1);
+-      if(!real_path) {
+-        free(working_path);
+-        return CURLE_OUT_OF_MEMORY;
+-      }
+-      memcpy(real_path, working_path, 1 + working_path_len);
++    /* Copy a separating '/' if homedir does not end with one */
++    len = Curl_dyn_len(&npath);
++    p = Curl_dyn_ptr(&npath);
++    if(len && (p[len-1] != '/'))
++      copyfrom = 2;
++
++    if(Curl_dyn_addn(&npath,
++                     &working_path[copyfrom], working_path_len - copyfrom)) {
++      free(working_path);
++      return CURLE_OUT_OF_MEMORY;
+     }
+   }
+ 
+-  free(working_path);
++  if(Curl_dyn_len(&npath)) {
++    free(working_path);
+ 
+-  /* store the pointer for the caller to receive */
+-  *path = real_path;
++    /* store the pointer for the caller to receive */
++    *path = Curl_dyn_ptr(&npath);
++  }
++  else
++    *path = working_path;
+ 
+   return CURLE_OK;
+ }
+-- 
+2.25.1
+
diff --git a/meta/recipes-support/curl/curl_7.82.0.bb b/meta/recipes-support/curl/curl_7.82.0.bb
index 7efec07e61..4c18afe293 100644
--- a/meta/recipes-support/curl/curl_7.82.0.bb
+++ b/meta/recipes-support/curl/curl_7.82.0.bb
@@ -41,6 +41,7 @@ SRC_URI = "https://curl.se/download/${BP}.tar.xz \
            file://CVE-2023-23914_5-5.patch \
            file://CVE-2023-23916.patch \
            file://CVE-2023-27533.patch \
+           file://CVE-2023-27534.patch \
            "
 SRC_URI[sha256sum] = "0aaa12d7bd04b0966254f2703ce80dd5c38dbbd76af0297d3d690cdce58a583c"