Re: tty: serial: lpuart driver (drivers/tty/serial/fsl_lpuart.c): commit 5887ad43ee02a00f1

["gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>]

On Fri, Jul 17, 2020 at 07:01:03AM +0000, Vabhav Sharma (OSS) wrote:
> Hello Greg, Bhuvanchandra DV,
> Static analysis tool is run against upstream kernel tree and found medium priority coverity issue against changes: commit 5887ad43ee02a00f17a6132b7fb256dc6865474c
> 
> Below are details
> sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1));
> 
> Bad bit shift operation, The operation may have an undefined behavior or yield an unexpected result.
> A bit shift operation has a shift amount which is too large or has a negative value.
> 
> zero_return: Function call fls(sport->rx_dma_rng_buf_len) returns 0
> CID 9000793 (#5 of 5):
> Bad bit shift operation (BAD_SHIFT)4. negative_shift: In expression 1 << fls(sport->rx_dma_rng_buf_len) - 1, shifting by a negative amount has undefined behavior. The shift amount, fls(sport->rx_dma_rng_buf_len) - 1, is -1.
> 
> Would you like to push changes for fixing the coverity issue.

Can you submit a patch for this, no need to make someone else do it :)

And note, html email is rejected by the mailing lists.

thanks,

greg k-h