Messages in this thread | | | Subject | Re: [PATCH 120/190] Revert "tty: atmel_serial: fix a potential NULL pointer dereference" | From | Richard Genoud <> | Date | Thu, 22 Apr 2021 06:47:20 +0000 |
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Le 22/04/2021 à 07:18, Jiri Slaby a écrit : > On 21. 04. 21, 14:59, Greg Kroah-Hartman wrote: >> 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> >> --- >> 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
> >> desc->callback = atmel_complete_rx_dma; >> desc->callback_param = port; >> atmel_port->desc_rx = desc; >> > >
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