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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 f429634..e17db4b 100644
--- a/lib/curl_path.c
+++ b/lib/curl_path.c
@@ -30,6 +30,8 @@
#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 connectdata *conn,
char *homedir, /* when SFTP is used */
@@ -37,60 +39,57 @@ CURLcode Curl_getworkingpath(struct connectdata *conn,
real path to work with */
{
struct Curl_easy *data = conn->data;
- char *real_path = NULL;
char *working_path;
size_t working_path_len;
+ struct dynbuf npath;
CURLcode result =
Curl_urldecode(data, data->state.up.path, 0, &working_path,
&working_path_len, FALSE);
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(conn->handler->protocol & CURLPROTO_SCP) {
- real_path = malloc(working_path_len + 1);
- if(real_path == NULL) {
+ 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(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 == NULL) {
- 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 == NULL) {
- 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
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