From: Jiri Slaby Date: Tue, 7 Aug 2012 19:47:39 +0000 (+0200) Subject: TTY: ttyprintk, don't touch behind tty->write_buf X-Git-Tag: firefly_0821_release~3680^2~1976^2~151 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ee8b593affdf893012e57f4c54a21984d1b0d92e;p=firefly-linux-kernel-4.4.55.git TTY: ttyprintk, don't touch behind tty->write_buf If a user provides a buffer larger than a tty->write_buf chunk and passes '\r' at the end of the buffer, we touch an out-of-bound memory. Add a check there to prevent this. Signed-off-by: Jiri Slaby Cc: stable@vger.kernel.org (everything maintained past v2.6.37) Cc: Samo Pogacnik Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c index 9b1e5e0cdc65..08755c52fc5f 100644 --- a/drivers/char/ttyprintk.c +++ b/drivers/char/ttyprintk.c @@ -67,7 +67,7 @@ static int tpk_printk(const unsigned char *buf, int count) tmp[tpk_curr + 1] = '\0'; printk(KERN_INFO "%s%s", tpk_tag, tmp); tpk_curr = 0; - if (buf[i + 1] == '\n') + if ((i + 1) < count && buf[i + 1] == '\n') i++; break; case '\n':