From 7e29e0278f228811f11e29b0692ada2f50fa7998 Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Thu, 25 Nov 2021 12:22:21 +0100 Subject: [PATCH] lavf/ftp: check for truncation in snprintf MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Silences e.g. the following warning in gcc 10: src/libavformat/ftp.c: In function ‘ftp_move’: src/libavformat/ftp.c:1122:46: warning: ‘%s’ directive output may be truncated writing up to 4095 bytes into a region of size 4091 [-Wformat-truncation=] 1122 | snprintf(command, sizeof(command), "RNTO %s\r\n", path); | ^~ ~~~~ src/libavformat/ftp.c:1122:5: note: ‘snprintf’ output between 8 and 4103 bytes into a destination of size 4096 1122 | snprintf(command, sizeof(command), "RNTO %s\r\n", path); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --- libavformat/ftp.c | 64 ++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 52 insertions(+), 12 deletions(-) diff --git a/libavformat/ftp.c b/libavformat/ftp.c index 69caa7670c..883668b37b 100644 --- a/libavformat/ftp.c +++ b/libavformat/ftp.c @@ -250,13 +250,19 @@ static int ftp_auth(FTPContext *s) if (strpbrk(s->user, "\r\n")) return AVERROR(EINVAL); - snprintf(buf, sizeof(buf), "USER %s\r\n", s->user); + err = snprintf(buf, sizeof(buf), "USER %s\r\n", s->user); + if (err >= sizeof(buf)) + return AVERROR(ENOSYS); + err = ftp_send_command(s, buf, user_codes, NULL); if (err == 331) { if (s->password) { if (strpbrk(s->password, "\r\n")) return AVERROR(EINVAL); - snprintf(buf, sizeof(buf), "PASS %s\r\n", s->password); + err = snprintf(buf, sizeof(buf), "PASS %s\r\n", s->password); + if (err >= sizeof(buf)) + return AVERROR(ENOSYS); + err = ftp_send_command(s, buf, pass_codes, NULL); } else return AVERROR(EACCES); @@ -397,9 +403,13 @@ static int ftp_file_size(FTPContext *s) { char command[CONTROL_BUFFER_SIZE]; char *res = NULL; + int ret; static const int size_codes[] = {213, 0}; - snprintf(command, sizeof(command), "SIZE %s\r\n", s->path); + ret = snprintf(command, sizeof(command), "SIZE %s\r\n", s->path); + if (ret >= sizeof(command)) + return AVERROR(ENOSYS); + if (ftp_send_command(s, command, size_codes, &res) == 213 && res && strlen(res) > 4) { s->filesize = strtoll(&res[4], NULL, 10); } else { @@ -416,9 +426,12 @@ static int ftp_retrieve(FTPContext *s) { char command[CONTROL_BUFFER_SIZE]; static const int retr_codes[] = {150, 125, 0}; - int resp_code; + int resp_code, ret; + + ret = snprintf(command, sizeof(command), "RETR %s\r\n", s->path); + if (ret >= sizeof(command)) + return AVERROR(ENOSYS); - snprintf(command, sizeof(command), "RETR %s\r\n", s->path); resp_code = ftp_send_command(s, command, retr_codes, NULL); if (resp_code != 125 && resp_code != 150) return AVERROR(EIO); @@ -432,9 +445,12 @@ static int ftp_store(FTPContext *s) { char command[CONTROL_BUFFER_SIZE]; static const int stor_codes[] = {150, 125, 0}; - int resp_code; + int resp_code, ret; + + ret = snprintf(command, sizeof(command), "STOR %s\r\n", s->path); + if (ret >= sizeof(command)) + return AVERROR(ENOSYS); - snprintf(command, sizeof(command), "STOR %s\r\n", s->path); resp_code = ftp_send_command(s, command, stor_codes, NULL); if (resp_code != 125 && resp_code != 150) return AVERROR(EIO); @@ -471,8 +487,12 @@ static int ftp_set_dir(FTPContext *s) { static const int cwd_codes[] = {250, 550, 0}; /* 550 is incorrect code */ char command[MAX_URL_SIZE]; + int ret; + + ret = snprintf(command, sizeof(command), "CWD %s\r\n", s->path); + if (ret >= sizeof(command)) + return AVERROR(ENOSYS); - snprintf(command, sizeof(command), "CWD %s\r\n", s->path); if (ftp_send_command(s, command, cwd_codes, NULL) != 250) return AVERROR(EIO); return 0; @@ -1082,13 +1102,23 @@ static int ftp_delete(URLContext *h) if ((ret = ftp_connect(h, h->filename)) < 0) goto cleanup; - snprintf(command, sizeof(command), "DELE %s\r\n", s->path); + ret = snprintf(command, sizeof(command), "DELE %s\r\n", s->path); + if (ret >= sizeof(command)) { + ret = AVERROR(ENOSYS); + goto cleanup; + } + if (ftp_send_command(s, command, del_codes, NULL) == 250) { ret = 0; goto cleanup; } - snprintf(command, sizeof(command), "RMD %s\r\n", s->path); + ret = snprintf(command, sizeof(command), "RMD %s\r\n", s->path); + if (ret >= sizeof(command)) { + ret = AVERROR(ENOSYS); + goto cleanup; + } + if (ftp_send_command(s, command, rmd_codes, NULL) == 250) ret = 0; else @@ -1110,7 +1140,12 @@ static int ftp_move(URLContext *h_src, URLContext *h_dst) if ((ret = ftp_connect(h_src, h_src->filename)) < 0) goto cleanup; - snprintf(command, sizeof(command), "RNFR %s\r\n", s->path); + ret = snprintf(command, sizeof(command), "RNFR %s\r\n", s->path); + if (ret >= sizeof(command)) { + ret = AVERROR(ENOSYS); + goto cleanup; + } + if (ftp_send_command(s, command, rnfr_codes, NULL) != 350) { ret = AVERROR(EIO); goto cleanup; @@ -1119,7 +1154,12 @@ static int ftp_move(URLContext *h_src, URLContext *h_dst) av_url_split(0, 0, 0, 0, 0, 0, 0, path, sizeof(path), h_dst->filename); - snprintf(command, sizeof(command), "RNTO %s\r\n", path); + ret = snprintf(command, sizeof(command), "RNTO %s\r\n", path); + if (ret >= sizeof(command)) { + ret = AVERROR(ENOSYS); + goto cleanup; + } + if (ftp_send_command(s, command, rnto_codes, NULL) == 250) ret = 0; else