| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 250/496] gpu: ipu-v3: prg: avoid possible array underflow | Date | Mon, 28 May 2018 12:00:35 +0200 |
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4.14-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann <arnd@arndb.de>
[ Upstream commit 746d024c3211813946b319411aeb2b47767f8fb0 ]
gcc-8 reports that we access an array with a negative index in an error case:
drivers/gpu/ipu-v3/ipu-prg.c: In function 'ipu_prg_channel_disable': drivers/gpu/ipu-v3/ipu-prg.c:252:43: error: array subscript -22 is below array bounds of 'struct ipu_prg_channel[3]' [-Werror=array-bounds]
This moves the range check in front of the first time that variable gets used.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/gpu/ipu-v3/ipu-prg.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/gpu/ipu-v3/ipu-prg.c +++ b/drivers/gpu/ipu-v3/ipu-prg.c @@ -252,10 +252,14 @@ void ipu_prg_channel_disable(struct ipuv { int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); struct ipu_prg *prg = ipu_chan->ipu->prg_priv; - struct ipu_prg_channel *chan = &prg->chan[prg_chan]; + struct ipu_prg_channel *chan; u32 val; - if (!chan->enabled || prg_chan < 0) + if (prg_chan < 0) + return; + + chan = &prg->chan[prg_chan]; + if (!chan->enabled) return; clk_prepare_enable(prg->clk_ipg); @@ -282,13 +286,15 @@ int ipu_prg_channel_configure(struct ipu { int prg_chan = ipu_prg_ipu_to_prg_chan(ipu_chan->num); struct ipu_prg *prg = ipu_chan->ipu->prg_priv; - struct ipu_prg_channel *chan = &prg->chan[prg_chan]; + struct ipu_prg_channel *chan; u32 val; int ret; if (prg_chan < 0) return prg_chan; + chan = &prg->chan[prg_chan]; + if (chan->enabled) { ipu_pre_update(prg->pres[chan->used_pre], *eba); return 0;
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