In atyfb_ioctl() structure atyclk is copied to userland with padding bytes after "vclk_post_div" field unitialized. It leads to leaking of contents of kernel stack memory. We have to initialize them to zero. Or it will allows local users to obtain potentially sensitive information from kernel stack memory by reading a copy of this structure. References: http://seclists.org/oss-sec/2017/q3/220 https://marc.info/?t=150401465500002&r=1&w=2 Suggested patch: https://github.com/torvalds/linux/pull/441 https://marc.info/?l=linux-fbdev&m=150401461113305&w=2
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1478019]
# CONFIG_FB_ATY is not set We don't enable this driver in fedora
Statement: This issue does not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5 and 7 as the code with the flaw is not present in the products listed. This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 6 and MRG-2. This has been rated as having Low security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.