Commit 57f31f058c29edfd7d6d810fcd4a964875e9d463
2013-08-08T11:05:00
Fixes to safely reading the index Avoid wrapping around extension size when reading, avoid walking off the end of the buffer when reading names.
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diff --git a/src/index.c b/src/index.c
index cbdd43b..5f53f1e 100644
--- a/src/index.c
+++ b/src/index.c
@@ -1371,7 +1371,7 @@ static int read_reuc(git_index *index, const char *buffer, size_t size)
while (size) {
git_index_reuc_entry *lost;
- len = strlen(buffer) + 1;
+ len = p_strnlen(buffer, size) + 1;
if (size <= len)
return index_error_invalid("reading reuc entries");
@@ -1444,7 +1444,7 @@ static int read_conflict_names(git_index *index, const char *buffer, size_t size
return -1;
#define read_conflict_name(ptr) \
- len = strlen(buffer) + 1; \
+ len = p_strnlen(buffer, size) + 1; \
if (size < len) \
return index_error_invalid("reading conflict name entries"); \
\
@@ -1571,7 +1571,8 @@ static size_t read_extension(git_index *index, const char *buffer, size_t buffer
total_size = dest.extension_size + sizeof(struct index_extension);
- if (buffer_size < total_size ||
+ if (dest.extension_size > total_size ||
+ buffer_size < total_size ||
buffer_size - total_size < INDEX_FOOTER_SIZE)
return 0;
diff --git a/src/posix.h b/src/posix.h
index 40bcc1a..ea97a13 100644
--- a/src/posix.h
+++ b/src/posix.h
@@ -93,6 +93,10 @@ extern int p_gettimeofday(struct timeval *tv, struct timezone *tz);
# include "unix/posix.h"
#endif
+#ifndef __MINGW32__
+# define p_strnlen strnlen
+#endif
+
#ifdef NO_READDIR_R
# include <dirent.h>
GIT_INLINE(int) p_readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
diff --git a/src/win32/mingw-compat.h b/src/win32/mingw-compat.h
index 7b97b48..97b1cb7 100644
--- a/src/win32/mingw-compat.h
+++ b/src/win32/mingw-compat.h
@@ -19,6 +19,11 @@
# define S_IFLNK _S_IFLNK
# define S_ISLNK(m) (((m) & _S_IFMT) == _S_IFLNK)
+GIT_INLINE(size_t) p_strnlen(const char *s, size_t maxlen) {
+ const char *end = memchr(s, 0, maxlen);
+ return end ? (end - s) : maxlen;
+}
+
#endif
#endif /* INCLUDE_mingw_compat__ */