Le 22/04/2021 à 07:18, Jiri Slaby a écrit :

On 21. 04. 21, 14:59, Greg Kroah-Hartman wrote:

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This reverts commit c85be041065c0be8bc48eda4c45e0319caf1d0e5.

Commits from @umn.edu addresses have been found to be submitted in "bad faith" to try to test the kernel community's ability to review "known malicious" changes.  The result of these submissions can be found in a paper published at the 42nd IEEE Symposium on Security and Privacy entitled, "Open Source Insecurity: Stealthily Introducing Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University of Minnesota) and Kangjie Lu (University of Minnesota).

Because of this, all submissions from this group must be reverted from the kernel tree and will need to be re-reviewed again to determine if they actually are a valid fix.  Until that work is complete, remove this change to ensure that no problems are being introduced into the codebase.

Cc: Kangjie Lu kjlu@umn.edu Cc: Richard Genoud richard.genoud@gmail.com Cc: stable stable@vger.kernel.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

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drivers/tty/serial/atmel_serial.c | 4 ----   1 file changed, 4 deletions(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index a24e5c2b30bc..9786d8e5f04f 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -1256,10 +1256,6 @@ static int atmel_prepare_rx_dma(struct uart_port *port)                        sg_dma_len(&atmel_port->sg_rx)/2,                        DMA_DEV_TO_MEM,                        DMA_PREP_INTERRUPT); -    if (!desc) { -        dev_err(port->dev, "Preparing DMA cyclic failed\n"); -        goto chan_err; -    }

I cannot find anything malicious in the original fix:

• port->dev is valid for dev_err
• dmaengine_prep_dma_cyclic returns NULL in case of error
• chan_err invokes atmel_release_rx_dma which undoes the previous initialization code.

Hence a NACK from me for the revert.

I agree with your NACK. Back at the time (march 2019), I reviewed the changed and asked for a 2nd version and I didn't found anything suspicious. But the more eyes, the better.

cf http://lkml.iu.edu/hypermail/linux/kernel/1903.1/05858.html

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desc->callback = atmel_complete_rx_dma;       desc->callback_param = port;       atmel_port->desc_rx = desc;