linux-kernel - [PATCH 2/3] staging: ion: Fix possible null pointer dereference

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <1387256873-21350-3-git-send-email-john.stultz@linaro.org>
Date:	Mon, 16 Dec 2013 21:07:52 -0800
From:	John Stultz <john.stultz@...aro.org>
To:	LKML <linux-kernel@...r.kernel.org>
Cc:	John Stultz <john.stultz@...aro.org>,
	Colin Cross <ccross@...roid.com>,
	Greg KH <gregkh@...uxfoundation.org>,
	Android Kernel Team <kernel-team@...roid.com>,
	kbuild test robot <fengguang.wu@...el.com>
Subject: [PATCH 2/3] staging: ion: Fix possible null pointer dereference

The kbuild test robot reported:

drivers/staging/android/ion/ion_system_heap.c:122 alloc_largest_available() error: potential null dereference 'info'.  (kmalloc returns null)

Where the pointer returned from kmalloc goes unchecked for failure.

This patch checks the return for NULL, and reworks the logic, as
suggested by Colin, so we allocate the page_info structure first.

Cc: Colin Cross <ccross@...roid.com>
Cc: Greg KH <gregkh@...uxfoundation.org>
Cc: Android Kernel Team <kernel-team@...roid.com>
Cc: kbuild test robot <fengguang.wu@...el.com>
Reported-by: kbuild test robot <fengguang.wu@...el.com>
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
 drivers/staging/android/ion/ion_system_heap.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index 144b2272..7f07291 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -108,6 +108,10 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
 	struct page_info *info;
 	int i;
 
+	info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
+	if (!info)
+		return NULL;
+
 	for (i = 0; i < num_orders; i++) {
 		if (size < order_to_size(orders[i]))
 			continue;
@@ -118,11 +122,12 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
 		if (!page)
 			continue;
 
-		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
 		info->page = page;
 		info->order = orders[i];
 		return info;
 	}
+	kfree(info);
+
 	return NULL;
 }
 
-- 
1.8.3.2

--
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/