Messages in this thread | | | Date | Thu, 22 Mar 2018 10:51:50 +0530 | From | Vinod Koul <> | Subject | Re: [PATCH v1 1/1] dmaengine: stm32-dmamux: fix a potential buffer overflow |
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On Tue, Mar 13, 2018 at 05:55:35PM +0100, Pierre-Yves MORDRET wrote: > The bitfield dma_inuse is allocated of size dma_requests bits, thus a > valid bit address is from 0 to (dma_requests - 1). > When find_first_zero_bit() fails, it returns dma_requests as invalid > address. > Using such address for the following set_bit() is incorrect and, if > dma_requests is a multiple of BITS_PER_LONG, it will cause a buffer > overflow. > Currently this driver is only used in DT stm32h743.dtsi where a safe value > dma_requests=16 is not triggering the buffer overflow. > > Fixed by checking the return value of find_first_zero_bit() _before_ > using it.
Applied, thanks
-- ~Vinod
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