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From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@armlinux.org.uk>,
	Adrian Salido <salidoa@google.com>,
	Nicolai Stange <nstange@suse.de>,
	Sasha Levin <Alexander.Levin@microsoft.com>,
	Todd Kjos <tkjos@android.com>,
	linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH v2 3/4] ARM: amba: Don't read past the end of sysfs "driver_override" buffer
Date: Tue, 10 Apr 2018 15:21:45 +0200	[thread overview]
Message-ID: <1523366506-19832-4-git-send-email-geert+renesas@glider.be> (raw)
In-Reply-To: <1523366506-19832-1-git-send-email-geert+renesas@glider.be>

When printing the driver_override parameter when it is 4095 and 4094
bytes long, the printing code would access invalid memory because we
need count + 1 bytes for printing.

Cfr. commits 4efe874aace57dba ("PCI: Don't read past the end of sysfs
"driver_override" buffer") and bf563b01c2895a4b ("driver core: platform:
Don't read past the end of "driver_override" buffer").

Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/amba/bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 36c5653ced5742b7..4a3ac31c07d0ee49 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -84,7 +84,8 @@ static ssize_t driver_override_store(struct device *_dev,
 	struct amba_device *dev = to_amba_device(_dev);
 	char *driver_override, *old, *cp;
 
-	if (count > PATH_MAX)
+	/* We need to keep extra room for a newline */
+	if (count >= (PAGE_SIZE - 1))
 		return -EINVAL;
 
 	driver_override = kstrndup(buf, count, GFP_KERNEL);
-- 
2.7.4

  parent reply	other threads:[~2018-04-10 13:21 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10 13:21 [PATCH v2 0/4] ARM: amba: driver_override improvements and fixes Geert Uytterhoeven
2018-04-10 13:21 ` [PATCH v2 1/4] ARM: amba: Make driver_override output consistent with other buses Geert Uytterhoeven
2018-04-25 15:53   ` Todd Kjos
2018-04-10 13:21 ` [PATCH v2 2/4] ARM: amba: Fix race condition with driver_override Geert Uytterhoeven
2018-04-25 15:56   ` Todd Kjos
2018-04-25 16:06   ` Greg Kroah-Hartman
2018-04-25 17:53     ` Geert Uytterhoeven
2018-04-26  7:04       ` Greg Kroah-Hartman
2018-04-26  7:40         ` Geert Uytterhoeven
2018-04-26  8:35           ` Greg Kroah-Hartman
2018-04-26  8:45             ` Geert Uytterhoeven
2018-05-09 10:39               ` Russell King - ARM Linux
2018-05-09 13:32                 ` Geert Uytterhoeven
2018-05-09 14:50                   ` Greg Kroah-Hartman
2018-04-10 13:21 ` Geert Uytterhoeven [this message]
2018-04-25 15:56   ` [PATCH v2 3/4] ARM: amba: Don't read past the end of sysfs "driver_override" buffer Todd Kjos
2018-04-10 13:21 ` [PATCH v2 4/4] ARM: amba: Fix wrong indentation in driver_override_store() Geert Uytterhoeven
2018-04-25 15:58   ` Todd Kjos
2018-04-10 22:19 ` [PATCH v2 0/4] ARM: amba: driver_override improvements and fixes Russell King - ARM Linux
2018-04-25 16:08   ` Greg Kroah-Hartman
2018-04-25 17:27   ` Geert Uytterhoeven

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