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* [PATCH] drm: bridge: sii8620: fix possible off-by-one
@ 2022-05-18  6:58 Hangyu Hua
  2022-05-18  7:57 ` Andrzej Hajda
  0 siblings, 1 reply; 4+ messages in thread
From: Hangyu Hua @ 2022-05-18  6:58 UTC (permalink / raw)
  To: andrzej.hajda, narmstrong, robert.foss, Laurent.pinchart, jonas,
	jernej.skrabec, airlied, daniel, architt
  Cc: dri-devel, linux-kernel, Hangyu Hua

The next call to sii8620_burst_get_tx_buf will result in off-by-one
When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The same
thing happens in sii8620_burst_get_rx_buf.

This patch also change tx_count and tx_buf to rx_count and rx_buf in
sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
use rx_buf.

Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC transmissions")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
---
 drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index ec7745c31da0..ab0bce4a988c 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct sii8620 *ctx, int len)
 	u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
 	int size = len + 2;
 
-	if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
+	if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
 		dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
 		ctx->error = -EINVAL;
 		return NULL;
@@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620 *ctx, int len)
 	u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
 	int size = len + 1;
 
-	if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
+	if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
 		dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
 		ctx->error = -EINVAL;
 		return NULL;
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-07-04 18:40 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-18  6:58 [PATCH] drm: bridge: sii8620: fix possible off-by-one Hangyu Hua
2022-05-18  7:57 ` Andrzej Hajda
2022-06-23  2:55   ` Hangyu Hua
2022-07-04 18:40     ` Robert Foss

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