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authorDan Carpenter <dan.carpenter@oracle.com>2016-08-10 16:27:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-10 16:40:56 -0700
commit73984137d32bb6e48646daea60ebe1457a01a061 (patch)
treea4bbaabb47be7b18460f32d887f99048b2aed327
parenta0cba2179ea4c1820fce2ee046b6ed90ecc56196 (diff)
downloadlinux-73984137d32bb6e48646daea60ebe1457a01a061.tar.bz2
rapidio: dereferencing an error pointer
Original patch: https://lkml.org/lkml/2016/8/4/32 If riocm_ch_alloc() fails then we end up dereferencing the error pointer. The problem is that we're not unwinding in the reverse order from how we allocate things so it gets confusing. I've changed this around so now "ch" is NULL when we are done with it after we call riocm_put_channel(). That way we can check if it's NULL and avoid calling riocm_put_channel() on it twice. I renamed err_nodev to err_put_new_ch so that it better reflects what the goto does. Then because we had flipping things around, it means we don't neeed to initialize the pointers to NULL and we can remove an if statement and pull things in an indent level. Link: http://lkml.kernel.org/r/20160805152406.20713-1-alexandre.bounine@idt.com Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Barry Wood <barry.wood@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rapidio/rio_cm.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index cecc15a880de..3fa17ac8df54 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -1080,8 +1080,8 @@ static int riocm_send_ack(struct rio_channel *ch)
static struct rio_channel *riocm_ch_accept(u16 ch_id, u16 *new_ch_id,
long timeout)
{
- struct rio_channel *ch = NULL;
- struct rio_channel *new_ch = NULL;
+ struct rio_channel *ch;
+ struct rio_channel *new_ch;
struct conn_req *req;
struct cm_peer *peer;
int found = 0;
@@ -1155,6 +1155,7 @@ static struct rio_channel *riocm_ch_accept(u16 ch_id, u16 *new_ch_id,
spin_unlock_bh(&ch->lock);
riocm_put_channel(ch);
+ ch = NULL;
kfree(req);
down_read(&rdev_sem);
@@ -1172,7 +1173,7 @@ static struct rio_channel *riocm_ch_accept(u16 ch_id, u16 *new_ch_id,
if (!found) {
/* If peer device object not found, simply ignore the request */
err = -ENODEV;
- goto err_nodev;
+ goto err_put_new_ch;
}
new_ch->rdev = peer->rdev;
@@ -1184,15 +1185,16 @@ static struct rio_channel *riocm_ch_accept(u16 ch_id, u16 *new_ch_id,
*new_ch_id = new_ch->id;
return new_ch;
+
+err_put_new_ch:
+ spin_lock_bh(&idr_lock);
+ idr_remove(&ch_idr, new_ch->id);
+ spin_unlock_bh(&idr_lock);
+ riocm_put_channel(new_ch);
+
err_put:
- riocm_put_channel(ch);
-err_nodev:
- if (new_ch) {
- spin_lock_bh(&idr_lock);
- idr_remove(&ch_idr, new_ch->id);
- spin_unlock_bh(&idr_lock);
- riocm_put_channel(new_ch);
- }
+ if (ch)
+ riocm_put_channel(ch);
*new_ch_id = 0;
return ERR_PTR(err);
}