From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: John Stultz <john.stultz@linaro.org>,
Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>,
dmaengine@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 09/26] dmaengine: k3dma: Avoid null pointer traversal
Date: Fri, 10 Jan 2020 17:05:02 -0500 [thread overview]
Message-ID: <20200110220519.28250-4-sashal@kernel.org> (raw)
In-Reply-To: <20200110220519.28250-1-sashal@kernel.org>
From: John Stultz <john.stultz@linaro.org>
[ Upstream commit 2f42e05b942fe2fbfb9bbc6e34e1dd8c3ce4f3a4 ]
In some cases we seem to submit two transactions in a row, which
causes us to lose track of the first. If we then cancel the
request, we may still get an interrupt, which traverses a null
ds_run value.
So try to avoid starting a new transaction if the ds_run value
is set.
While this patch avoids the null pointer crash, I've had some
reports of the k3dma driver still getting confused, which
suggests the ds_run/ds_done value handling still isn't quite
right. However, I've not run into an issue recently with it
so I think this patch is worth pushing upstream to avoid the
crash.
Signed-off-by: John Stultz <john.stultz@linaro.org>
[add ss tag]
Link: https://lore.kernel.org/r/20191218190906.6641-1-john.stultz@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/k3dma.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
index 4b36c8810517..d05471653224 100644
--- a/drivers/dma/k3dma.c
+++ b/drivers/dma/k3dma.c
@@ -229,9 +229,11 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
c = p->vchan;
if (c && (tc1 & BIT(i))) {
spin_lock_irqsave(&c->vc.lock, flags);
- vchan_cookie_complete(&p->ds_run->vd);
- p->ds_done = p->ds_run;
- p->ds_run = NULL;
+ if (p->ds_run != NULL) {
+ vchan_cookie_complete(&p->ds_run->vd);
+ p->ds_done = p->ds_run;
+ p->ds_run = NULL;
+ }
spin_unlock_irqrestore(&c->vc.lock, flags);
}
if (c && (tc2 & BIT(i))) {
@@ -271,6 +273,10 @@ static int k3_dma_start_txd(struct k3_dma_chan *c)
if (BIT(c->phy->idx) & k3_dma_get_chan_stat(d))
return -EAGAIN;
+ /* Avoid losing track of ds_run if a transaction is in flight */
+ if (c->phy->ds_run)
+ return -EAGAIN;
+
if (vd) {
struct k3_dma_desc_sw *ds =
container_of(vd, struct k3_dma_desc_sw, vd);
--
2.20.1
next prev parent reply other threads:[~2020-01-10 22:08 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 22:04 [PATCH AUTOSEL 5.4 06/26] rxrpc: Unlock new call in rxrpc_new_incoming_call() rather than the caller Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 07/26] rxrpc: Don't take call->user_mutex in rxrpc_new_incoming_call() Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 08/26] rxrpc: Fix missing security check on incoming calls Sasha Levin
2020-01-10 22:05 ` Sasha Levin [this message]
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 10/26] s390/qeth: fix qdio teardown after early init error Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 11/26] s390/qeth: lock the card while changing its hsuid Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 12/26] s390/qeth: fix false reporting of VNIC CHAR config failure Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 13/26] s390/qeth: Fix vnicc_is_in_use if rx_bcast not set Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 14/26] s390/qeth: vnicc Fix init to default Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 15/26] s390/qeth: fix initialization on old HW Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 16/26] hsr: add hsr root debugfs directory Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 17/26] hsr: rename debugfs file when interface name is changed Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 18/26] hsr: reset network header when supervision frame is created Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 19/26] ioat: ioat_alloc_ring() failure handling Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 20/26] drm/amdgpu: enable gfxoff for raven1 refresh Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 21/26] hsr: fix slab-out-of-bounds Read in hsr_debugfs_rename() Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 22/26] media: intel-ipu3: Align struct ipu3_uapi_awb_fr_config_s to 32 bytes Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 23/26] kbuild/deb-pkg: annotate libelf-dev dependency as :native Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 24/26] hexagon: parenthesize registers in asm predicates Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 25/26] hexagon: work around compiler crash Sasha Levin
2020-01-10 22:05 ` [PATCH AUTOSEL 5.4 26/26] ocfs2: call journal flush to mark journal as empty after journal recovery when mount Sasha Levin
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