wget: check chunk length for overflowing off_t
function old new delta
retrieve_file_data 428 465 +37
wget_main 2386 2389 +3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 40/0) Total: 40 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/wget.c b/networking/wget.c
index c9e576e..2650b53 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -801,7 +801,7 @@
if (ftpcmd("SIZE ", target->path, sfp) == 213) {
G.content_len = BB_STRTOOFF(G.wget_buf + 4, NULL, 10);
if (G.content_len < 0 || errno) {
- bb_error_msg_and_die("SIZE value is garbage");
+ bb_error_msg_and_die("bad SIZE value '%s'", G.wget_buf + 4);
}
G.got_clen = 1;
}
@@ -965,11 +965,19 @@
if (!G.chunked)
break;
- fgets_trim_sanitize(dfp, NULL); /* Eat empty line */
- get_clen:
+ /* Each chunk ends with "\r\n" - eat it */
fgets_trim_sanitize(dfp, NULL);
+ get_clen:
+ /* chunk size format is "HEXNUM[;name[=val]]\r\n" */
+ fgets_trim_sanitize(dfp, NULL);
+ errno = 0;
G.content_len = STRTOOFF(G.wget_buf, NULL, 16);
- /* FIXME: error check? */
+ /*
+ * Had a bug with inputs like "ffffffff0001f400"
+ * smashing the heap later. Ensure >= 0.
+ */
+ if (G.content_len < 0 || errno)
+ bb_error_msg_and_die("bad chunk length '%s'", G.wget_buf);
if (G.content_len == 0)
break; /* all done! */
G.got_clen = 1;