From: Chen Gang Date: Thu, 7 Mar 2013 18:25:41 +0000 (+0000) Subject: drivers/isdn: checkng length to be sure not memory overflow X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f39479363e0361c8bb4397481c01a7c3a1a3c8ac;p=linux-beck.git drivers/isdn: checkng length to be sure not memory overflow sizeof (cmd.parm.cmsg.para) is 50 (MAX_CAPI_PARA_LEN). sizeof (cmd.parm) is 80+, but less than 100. strlen(msg) may be more than 80+ (Modem-Commandbuffer, less than 255). isdn_tty_send_msg is called by isdn_tty_parse_at the relative parameter is m->mdmcmd (atemu *m) the relative command may be "+M..." so need check the length to be sure not memory overflow. cmd.parm is a union, and need keep original valid buffer length no touch Signed-off-by: Chen Gang Signed-off-by: David S. Miller --- diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c index d8a7d8323414..ebaebdf30f98 100644 --- a/drivers/isdn/i4l/isdn_tty.c +++ b/drivers/isdn/i4l/isdn_tty.c @@ -902,7 +902,9 @@ isdn_tty_send_msg(modem_info *info, atemu *m, char *msg) int j; int l; - l = strlen(msg); + l = min(strlen(msg), sizeof(cmd.parm) - sizeof(cmd.parm.cmsg) + + sizeof(cmd.parm.cmsg.para) - 2); + if (!l) { isdn_tty_modem_result(RESULT_ERROR, info); return;