This is a note to let you know that I've just added the patch titled drm: bridge: sii8620: fix possible off-by-one to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-bridge-sii8620-fix-possible-off-by-one.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 140a06fd48911d0e7e9f390d8b83cf4956c5e81a Author: Hangyu Hua <hbh25y@xxxxxxxxx> Date: Wed May 18 14:58:56 2022 +0800 drm: bridge: sii8620: fix possible off-by-one [ Upstream commit 21779cc21c732c5eff8ea1624be6590450baa30f ] 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@xxxxxxxxx> Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20220518065856.18936-1-hbh25y@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c index ea433bb189ca..c72092319a53 100644 --- a/drivers/gpu/drm/bridge/sil-sii8620.c +++ b/drivers/gpu/drm/bridge/sil-sii8620.c @@ -607,7 +607,7 @@ 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; @@ -624,7 +624,7 @@ 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;