This is a note to let you know that I've just added the patch titled i2c: ismt: Return EMSGSIZE for block reads with bogus length to the 4.9-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: i2c-ismt-return-emsgsize-for-block-reads-with-bogus-length.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ba201c4f5ebe13d7819081756378777d8153f23e Mon Sep 17 00:00:00 2001 From: Stephen Douthit <stephend@xxxxxxxxxxxxxxxxxx> Date: Mon, 7 Aug 2017 17:11:00 -0400 Subject: i2c: ismt: Return EMSGSIZE for block reads with bogus length From: Stephen Douthit <stephend@xxxxxxxxxxxxxxxxxx> commit ba201c4f5ebe13d7819081756378777d8153f23e upstream. Compare the number of bytes actually seen on the wire to the byte count field returned by the slave device. Previously we just overwrote the byte count returned by the slave with the real byte count and let the caller figure out if the message was sane. Signed-off-by: Stephen Douthit <stephend@xxxxxxxxxxxxxxxxxx> Tested-by: Dan Priamo <danp@xxxxxxxxxxxxxxxxxx> Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-ismt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -341,8 +341,10 @@ static int ismt_process_desc(const struc break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_I2C_BLOCK_DATA: + if (desc->rxbytes != dma_buffer[0] + 1) + return -EMSGSIZE; + memcpy(data->block, dma_buffer, desc->rxbytes); - data->block[0] = desc->rxbytes - 1; break; } return 0; Patches currently in stable-queue which might be from stephend@xxxxxxxxxxxxxxxxxx are queue-4.9/i2c-ismt-don-t-duplicate-the-receive-length-for-block-reads.patch queue-4.9/i2c-ismt-return-emsgsize-for-block-reads-with-bogus-length.patch