printk: fix string termination for record_print_text()

Commit f0e386ee0c ("printk: fix buffer overflow potential for
print_text()") added string termination in record_print_text().
However it used the wrong base pointer for adding the terminator.
This led to a 0-byte being written somewhere beyond the buffer.

Use the correct base pointer when adding the terminator.

Fixes: f0e386ee0c ("printk: fix buffer overflow potential for print_text()")
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210124202728.4718-1-john.ogness@linutronix.de
This commit is contained in:
John Ogness 2021-01-24 21:33:28 +01:06 committed by Petr Mladek
parent f0e386ee0c
commit 08d60e5999

View File

@ -1399,7 +1399,7 @@ static size_t record_print_text(struct printk_record *r, bool syslog,
* not counted in the return value.
*/
if (buf_size > 0)
text[len] = 0;
r->text_buf[len] = 0;
return len;
}