[PATCH AUTOSEL 4.4 1/2] dmaengine: ti: omap-dma: Add cleanup in omap_dma_probe()

[PATCH AUTOSEL 4.4 1/2] dmaengine: ti: omap-dma: Add cleanup in omap_dma_probe()

[Sasha Levin]

From: Wenwen Wang <wenwen@cs.uga.edu>

[ Upstream commit 962411b05a6d3342aa649e39cda1704c1fc042c6 ]

If devm_request_irq() fails to disable all interrupts, no cleanup is
performed before retuning the error. To fix this issue, invoke
omap_dma_free() to do the cleanup.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/1565938570-7528-1-git-send-email-wenwen@cs.uga.edu
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/omap-dma.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 1dfc71c90123f..57b6e6ca14a88 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -1199,8 +1199,10 @@ static int omap_dma_probe(struct platform_device *pdev)
 
 		rc = devm_request_irq(&pdev->dev, irq, omap_dma_irq,
 				      IRQF_SHARED, "omap-dma-engine", od);
-		if (rc)
+		if (rc) {
+			omap_dma_free(od);
 			return rc;
+		}
 	}
 
 	rc = dma_async_device_register(&od->ddev);
-- 
2.20.1

[PATCH AUTOSEL 4.4 2/2] keys: Fix missing null pointer check in request_key_auth_describe()

[Sasha Levin]

From: Hillf Danton <hdanton@sina.com>

[ Upstream commit d41a3effbb53b1bcea41e328d16a4d046a508381 ]

If a request_key authentication token key gets revoked, there's a window in
which request_key_auth_describe() can see it with a NULL payload - but it
makes no check for this and something like the following oops may occur:

	BUG: Kernel NULL pointer dereference at 0x00000038
	Faulting instruction address: 0xc0000000004ddf30
	Oops: Kernel access of bad area, sig: 11 [#1]
	...
	NIP [...] request_key_auth_describe+0x90/0xd0
	LR [...] request_key_auth_describe+0x54/0xd0
	Call Trace:
	[...] request_key_auth_describe+0x54/0xd0 (unreliable)
	[...] proc_keys_show+0x308/0x4c0
	[...] seq_read+0x3d0/0x540
	[...] proc_reg_read+0x90/0x110
	[...] __vfs_read+0x3c/0x70
	[...] vfs_read+0xb4/0x1b0
	[...] ksys_read+0x7c/0x130
	[...] system_call+0x5c/0x70

Fix this by checking for a NULL pointer when describing such a key.

Also make the read routine check for a NULL pointer to be on the safe side.

[DH: Modified to not take already-held rcu lock and modified to also check
 in the read routine]

Fixes: 04c567d9313e ("[PATCH] Keys: Fix race between two instantiators of a key")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/keys/request_key_auth.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 8882b729924dd..976deea0569e3 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -71,6 +71,9 @@ static void request_key_auth_describe(const struct key *key,
 {
 	struct request_key_auth *rka = key->payload.data[0];
 
+	if (!rka)
+		return;
+
 	seq_puts(m, "key:");
 	seq_puts(m, key->description);
 	if (key_is_positive(key))
@@ -88,6 +91,9 @@ static long request_key_auth_read(const struct key *key,
 	size_t datalen;
 	long ret;
 
+	if (!rka)
+		return -EKEYREVOKED;
+
 	datalen = rka->callout_len;
 	ret = datalen;
 
-- 
2.20.1