[tor-commits] [tor/master] hs-v3: Fix possible memory leak in error code path

[teor at torproject.org]

commit 09e6c0f7c7b91a73c73df197e45072a96240ea8d
Author: David Goulet <dgoulet at torproject.org>
Date:   Tue Oct 15 08:54:11 2019 -0400

    hs-v3: Fix possible memory leak in error code path
    
    Found by coverity CID 1454769.
    
    There were a second possible leak that is also fixed in this commit.
    
    Fixes #32063
    
    Signed-off-by: David Goulet <dgoulet at torproject.org>
---
 changes/ticket32063      |  3 +++
 src/feature/hs/hs_cell.c | 13 +++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/changes/ticket32063 b/changes/ticket32063
new file mode 100644
index 000000000..2c0246917
--- /dev/null
+++ b/changes/ticket32063
@@ -0,0 +1,3 @@
+  o Minor bugfixes (hs-v3, memory leak):
+    - Fix memory leak in unlikely error code path when encoding HS DoS establish
+      intro extension cell. Fixes bug 32063; bugfix on 0.4.2.1-alpha.
diff --git a/src/feature/hs/hs_cell.c b/src/feature/hs/hs_cell.c
index d691a1b00..df59f73c1 100644
--- a/src/feature/hs/hs_cell.c
+++ b/src/feature/hs/hs_cell.c
@@ -503,8 +503,8 @@ build_establish_intro_dos_extension(const hs_service_config_t *service_config,
   ssize_t ret;
   size_t dos_ext_encoded_len;
   uint8_t *field_array;
-  trn_cell_extension_field_t *field;
-  trn_cell_extension_dos_t *dos_ext;
+  trn_cell_extension_field_t *field = NULL;
+  trn_cell_extension_dos_t *dos_ext = NULL;
 
   tor_assert(service_config);
   tor_assert(extensions);
@@ -530,7 +530,7 @@ build_establish_intro_dos_extension(const hs_service_config_t *service_config,
   /* Set the field with the encoded DoS extension. */
   ret = trn_cell_extension_dos_encoded_len(dos_ext);
   if (BUG(ret <= 0)) {
-    return -1;
+    goto err;
   }
   dos_ext_encoded_len = ret;
   /* Set length field and the field array size length. */
@@ -541,7 +541,7 @@ build_establish_intro_dos_extension(const hs_service_config_t *service_config,
   ret = trn_cell_extension_dos_encode(field_array,
                  trn_cell_extension_field_getlen_field(field), dos_ext);
   if (BUG(ret <= 0)) {
-    return -1;
+    goto err;
   }
   tor_assert(ret == (ssize_t) dos_ext_encoded_len);
 
@@ -557,6 +557,11 @@ build_establish_intro_dos_extension(const hs_service_config_t *service_config,
   trn_cell_extension_dos_free(dos_ext);
 
   return 0;
+
+ err:
+  trn_cell_extension_field_free(field);
+  trn_cell_extension_dos_free(dos_ext);
+  return -1;
 }
 
 /* ========== */