On Sun, May 16, 2021 at 11:00:19PM +0800, kernel test robot wrote:
Greeting,
FYI, we noticed the following commit (built with gcc-9):
commit: dc13cac4862cc68ec74348a80b6942532b7735fa ("video: hgafb: fix potential NULL pointer dereference") https://git.kernel.org/cgit/linux/kernel/git/gregkh/char-misc.git char-misc-linus
in testcase: trinity version: trinity-static-x86_64-x86_64-f93256fb_2019-08-28 with following parameters:
number: 99999 group: group-02
test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/
on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
+---------------------------------------------+------------+------------+ | | 58c0cc2d90 | dc13cac486 | +---------------------------------------------+------------+------------+ | boot_successes | 42 | 14 | | boot_failures | 0 | 34 | | BUG:KASAN:stack-out-of-bounds_in_hgafb_open | 0 | 34 | +---------------------------------------------+------------+------------+
If you fix the issue, kindly add following tag Reported-by: kernel test robot oliver.sang@intel.com
[ 419.568887] BUG: KASAN: stack-out-of-bounds in hgafb_open (kbuild/src/consumer/drivers/video/fbdev/hgafb.c:375)
Looks like the return value of hga_card_detect() is not properly handled causing the probe function to succeed even though hga_card_detect() has failed. Since probe has succeeded, hgafb_open() can be called which will end up operating on an unmapped hga_vram.
Patch on the way.
Thanks!
- Anirudh.