linux-kernel - [PATCH] remoteproc: avoid stack overflow in debugfs file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 20 Nov 2015 18:26:07 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	Ohad Ben-Cohen <ohad@...ery.com>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Fernando Guzman Lugo <fernando.lugo@...com>,
	Fernando Guzman Lugo <fernando.guzman.lugo@...el.com>
Subject: [PATCH] remoteproc: avoid stack overflow in debugfs file

Recent gcc versions warn about reading from a negative offset of
an on-stack array:

drivers/remoteproc/remoteproc_debugfs.c: In function 'rproc_recovery_write':
drivers/remoteproc/remoteproc_debugfs.c:167:9: warning: 'buf[4294967295u]' may be used uninitialized in this function [-Wmaybe-uninitialized]

I don't see anything in sys_write() that prevents us from
being called with a zero 'count' argument, so we should
add an extra check in rproc_recovery_write() to prevent the
access and avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
Fixes: 2e37abb89a2e ("remoteproc: create a 'recovery' debugfs entry")

diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c
index 9d30809bb407..916af5096f57 100644
--- a/drivers/remoteproc/remoteproc_debugfs.c
+++ b/drivers/remoteproc/remoteproc_debugfs.c
@@ -156,7 +156,7 @@ rproc_recovery_write(struct file *filp, const char __user *user_buf,
 	char buf[10];
 	int ret;
 
-	if (count > sizeof(buf))
+	if (count < 1 || count > sizeof(buf))
 		return count;
 
 	ret = copy_from_user(buf, user_buf, count);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/