From e18ed145c7f556f1de8350c32739bf35b26df705 Mon Sep 17 00:00:00 2001
From: Christian Engelmayer <christian.engelmayer@frequentis.com>
Date: Mon, 29 Jun 2009 19:31:41 -0700
Subject: [PATCH] ide: memory overrun in ide_get_identity_ioctl() on big endian
 machines using ioctl HDIO_OBSOLETE_IDENTITY

This patch fixes a memory overrun in function ide_get_identity_ioctl() which
chooses the size of a memory buffer depending on the ioctl command that led
to the function call, however, passes that buffer to a function which needs the
buffer size to be always chosen unconditionally.

Due to conditional compilation the memory overrun can only happen on big endian
machines. The error can be triggered using ioctl HDIO_OBSOLETE_IDENTITY. Usage
of ioctl HDIO_GET_IDENTITY is safe.

Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/ide/ide-ioctls.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 82f252c3ee6e5..e246d3d3fbcc5 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -64,7 +64,8 @@ static int ide_get_identity_ioctl(ide_drive_t *drive, unsigned int cmd,
 		goto out;
 	}
 
-	id = kmalloc(size, GFP_KERNEL);
+	/* ata_id_to_hd_driveid() relies on 'id' to be fully allocated. */
+	id = kmalloc(ATA_ID_WORDS * 2, GFP_KERNEL);
 	if (id == NULL) {
 		rc = -ENOMEM;
 		goto out;
-- 
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