From 21779cc21c732c5eff8ea1624be6590450baa30f Mon Sep 17 00:00:00 2001 From: Hangyu Hua Date: Wed, 18 May 2022 14:58:56 +0800 Subject: [PATCH] drm: bridge: sii8620: fix possible off-by-one 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 Reviewed-by: Andrzej Hajda Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220518065856.18936-1-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 ec7745c..ab0bce4 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; -- 2.7.4