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From: sohu0106 <sohu0106@126.com>
To: schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com
Cc: linux-s390@vger.kernel.org, torvalds@linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: drivers/s390/char/keyboard.c kernel stack infoleak
Date: Thu, 3 Aug 2017 21:59:31 +0800 (CST)	[thread overview]
Message-ID: <116f735.aa23.15da864e94a.Coremail.sohu0106@126.com> (raw)


The stack object "kbdiacr" has a total size of 4 bytes. Its last 1 bytes are padding bytes after "result" which are not initialized and leaked to userland via "copy_to_user".


diff --git a/keyboard.c b/keyboard.c
index ba0e4f9..76a6d35 100644
--- a/keyboard.c
+++ b/keyboard.c
@@ -480,6 +480,8 @@ int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
                struct kbdiacr diacr;
                int i;
 
+               memset( &diacr, 0, sizeof(struct kbdiacr) );
+
                if (put_user(kbd->accent_table_size, &a->kb_cnt))
                        return -EFAULT;
                for (i = 0; i < kbd->accent_table_size; i++) {

             reply	other threads:[~2017-08-03 13:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-03 13:59 sohu0106 [this message]
2017-08-04  9:09 ` drivers/s390/char/keyboard.c kernel stack infoleak Thomas Huth
2017-08-04  9:20   ` Heiko Carstens
     [not found]     ` <78655e6a.d34.15db01cd5b8.Coremail.sohu0106@126.com>
2017-08-05  7:12       ` Thomas Huth

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