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wget: check chunk length for overflowing off_t

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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>
This commit is contained in:
Denys Vlasenko
2018-04-08 18:06:24 +02:00
parent 7bcde5f00d
commit 8e2174e9bd
1 changed files with 12 additions and 4 deletions
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16
networking/wget.c
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@@ -801,7 +801,7 @@ static FILE* prepare_ftp_session(FILE **dfpp, struct host_info *target, len_and_
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 @@ static void NOINLINE retrieve_file_data(FILE *dfp)
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;