On Sat, Jan 12, 2019 at 04:28:40PM +0100, Willy Tarreau wrote: > From: Silvio Cesare <[email protected]> > > Change snprintf to scnprintf. There are generally two cases where using > snprintf causes problems. > > 1) Uses of size += snprintf(buf, SIZE - size, fmt, ...) > In this case, if snprintf would have written more characters than what the > buffer size (SIZE) is, then size will end up larger than SIZE. In later > uses of snprintf, SIZE - size will result in a negative number, leading > to problems. Note that size might already be too large by using > size = snprintf before the code reaches a case of size += snprintf. > > 2) If size is ultimately used as a length parameter for a copy back to user > space, then it will potentially allow for a buffer overflow and information > disclosure when size is greater than SIZE. When the size is used to index > the buffer directly, we can have memory corruption. This also means when > size = snprintf... is used, it may also cause problems since size may become > large. Copying to userspace is mitigated by the HARDENED_USERCOPY kernel > configuration. > > The solution to these issues is to use scnprintf which returns the number of > characters actually written to the buffer, so the size variable will never > exceed SIZE. > > Signed-off-by: Silvio Cesare <[email protected]>
> Cc: Nicolin Chen <[email protected]> I think you probably need to run get_maintainer.pl for the patch and should send to Mark Brown and CC alsa-devel. And for subject, we usually use prefix "ASoC: imx-audmux:". Otherwise, Acked-by: Nicolin Chen <[email protected]> Thanks
