linux-kernel - [PATCH 2/2] arch/arm/common: Eliminate use after free

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>] [day] [month] [year] [list]

Date:	Fri, 30 Jul 2010 17:17:28 +0200 (CEST)
From:	Julia Lawall <julia@...u.dk>
To:	Russell King <linux@....linux.org.uk>,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: [PATCH 2/2] arch/arm/common: Eliminate use after free

From: Julia Lawall <julia@...u.dk>

__sa1111_remove always frees its argument, so the subsequent reference to
sachip->saved_state represents a use after free.  __sa1111_remove does not
appear to use the saved_state field, so the patch simply frees it first.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E,E2;
@@

__sa1111_remove(E)
...
(
  E = E2
|
* E
)
// </smpl>

Signed-off-by: Julia Lawall <julia@...u.dk>

---
arch/arm/common/sa1111.c            |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm/common/sa1111.c b/arch/arm/common/sa1111.c
index ac2fd44..517d50d 100644
--- a/arch/arm/common/sa1111.c
+++ b/arch/arm/common/sa1111.c
@@ -1025,13 +1025,12 @@ static int sa1111_remove(struct platform_device *pdev)
 	struct sa1111 *sachip = platform_get_drvdata(pdev);
 
 	if (sachip) {
-		__sa1111_remove(sachip);
-		platform_set_drvdata(pdev, NULL);
-
 #ifdef CONFIG_PM
 		kfree(sachip->saved_state);
 		sachip->saved_state = NULL;
 #endif
+		__sa1111_remove(sachip);
+		platform_set_drvdata(pdev, NULL);
 	}
 
 	return 0;
--
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/