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| author | Denys Vlasenko | 2018-04-08 18:06:24 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2018-04-08 18:06:24 +0200 |
| commit | 8e2174e9bd836e53c8b9c6e00d1bc6e2a718686e (patch) | |
| tree | eea0f2855d6cc97b50e979e280e39d7d6497bf9d | |
| parent | 7bcde5f00dc3a5c92f36bb6ef6bf849794cd766e (diff) | |
| download | busybox-8e2174e9bd836e53c8b9c6e00d1bc6e2a718686e.zip busybox-8e2174e9bd836e53c8b9c6e00d1bc6e2a718686e.tar.gz | |
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>
| -rw-r--r-- | networking/wget.c | 14 |
1 files changed, 11 insertions, 3 deletions
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 @@ 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 */ + /* 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; |