Author: brane
Date: Sun Oct 14 02:53:08 2018
New Revision: 1843807
URL: http://svn.apache.org/viewvc?rev=1843807&view=rev
Log:
Restrict the loaded-library list on Linux to shared libraries.
* subversion/libsvn_subr/sysinfo.c (linux_shared_libs):
Show only mapped files that start with an ELF header that has
the correct type.
Modified:
subversion/trunk/subversion/libsvn_subr/sysinfo.c
Modified: subversion/trunk/subversion/libsvn_subr/sysinfo.c
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/sysinfo.c?rev=1843807&r1=1843806&r2=1843807&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/sysinfo.c (original)
+++ subversion/trunk/subversion/libsvn_subr/sysinfo.c Sun Oct 14 02:53:08 2018
@@ -697,6 +697,8 @@ linux_shared_libs(apr_pool_t *pool)
while (!eof)
{
svn_stringbuf_t *line;
+ const unsigned char *map_start;
+ const unsigned char *map_end;
err = svn_stream_readline(stream, &line, "\n", &eof, pool);
if (err)
@@ -705,7 +707,28 @@ linux_shared_libs(apr_pool_t *pool)
return NULL;
}
- /* Find the permissions of the mapped region. */
+ /* Address: The mapped memory address range. */
+ {
+ const char *const limit = line->data + line->len;
+ const char *start;
+ apr_int64_t val;
+ char *end;
+
+ /* The start of the address range */
+ start = line->data;
+ val = apr_strtoi64(start, &end, 16);
+ if (end == start || end >= limit || *end != '-')
+ continue;
+ map_start = (const unsigned char*)val;
+
+ /* The end of the address range */
+ start = end + 1;
+ val = apr_strtoi64(start, &end, 16);
+ if (end == start || end >= limit || !svn_ctype_isspace(*end))
+ continue;
+ map_end = (const unsigned char*)val;
+ }
+
stringbuf_skip_whitespace_field(line); /* skip address */
/* Permissions: The memory region must be readable and executable. */
@@ -723,13 +746,39 @@ linux_shared_libs(apr_pool_t *pool)
stringbuf_skip_whitespace_field(line); /* skip inode */
- /* Record anything that looks like an absolute path.
+ /* Consider only things that look like absolute paths.
Files that were removed since the process was created (due to an
upgrade, for example) are marked as '(deleted)'. */
if (line->data[0] == '/')
{
svn_version_ext_loaded_lib_t *lib;
+ /* Read the ELF header at the mapping position to check if this is
+ a shared library. We only look at the ELF identification and the
+ type. The format is described here:
+ http://www.skyfree.org/linux/references/ELF_Format.pdf
+ */
+ if (map_end - map_start < 18 || memcmp(map_start, "\x7f" "ELF", 4))
+ continue;
+
+ /* The ELF Type is 0x0003 for shared object files. */
+ switch (map_start[5]) /* Data encoding */
+ {
+ case 1: /* Little-Endian */
+ if (map_start[16] != 3 || map_start[17] != 0)
+ continue;
+ break;
+
+ case 2: /* Big-Endian */
+ if (map_start[16] != 0 || map_start[17] != 3)
+ continue;
+ break;
+
+ default:
+ continue;
+ }
+
+ /* We've done our best to find a mapped shared library. */
if (!result)
{
result = apr_array_make(pool, 32, sizeof(*lib));
