linux-kernel - [PATCH 5/11] drivers/dma: Eliminate a 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>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.64.1005271433000.5422@ask.diku.dk>
Date:	Thu, 27 May 2010 14:33:17 +0200 (CEST)
From:	Julia Lawall <julia@...u.dk>
To:	Dan Williams <dan.j.williams@...el.com>,
	linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: [PATCH 5/11] drivers/dma: Eliminate a NULL pointer dereference

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

If td_desc is NULL, just skip both kfrees.

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

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E == NULL && ...) || ...)
{
  ... when != if (...) S1 else S2
      when != E = E1
* E->f
  ... when any
  return ...;
}
else S3
// </smpl>

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

---
 drivers/dma/timb_dma.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/timb_dma.c b/drivers/dma/timb_dma.c
index 0172fa3..c4eb96a 100644
--- a/drivers/dma/timb_dma.c
+++ b/drivers/dma/timb_dma.c
@@ -382,7 +382,7 @@ static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
 	td_desc = kzalloc(sizeof(struct timb_dma_desc), GFP_KERNEL);
 	if (!td_desc) {
 		dev_err(chan2dev(chan), "Failed to alloc descriptor\n");
-		goto err;
+		goto out;
 	}
 
 	td_desc->desc_list_len = td_chan->desc_elems * TIMB_DMA_DESC_SIZE;
@@ -410,7 +410,7 @@ static struct timb_dma_desc *td_alloc_init_desc(struct timb_dma_chan *td_chan)
 err:
 	kfree(td_desc->desc_list);
 	kfree(td_desc);
-
+out:
 	return NULL;
 
 }
--
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/