> -----Original Message----- > From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> > Sent: Wednesday, May 27, 2020 9:02 PM > To: Ashwin H <ashwinh@xxxxxxxxxx> > Cc: x86@xxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; intel- > gfx@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxx; > Srivatsa Bhat <srivatsab@xxxxxxxxxx>; srivatsa@xxxxxxxxxxxxx; > rostedt@xxxxxxxxxxx; Steven Rostedt <srostedt@xxxxxxxxxx>; Linus > Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Subject: Re: [PATCH v4.19.x] make 'user_access_begin()' do 'access_ok()' > > On Wed, May 13, 2020 at 05:08:19PM +0000, Ashwin H wrote: > > > Ok, but what does that mean for us? > > > > > > You need to say why you are sending a patch, otherwise we will guess > wrong. > > > > In drivers/gpu/drm/i915/i915_gem_execbuffer.c, ioctl functions does > user_access_begin() without doing access_ok(Checks if a user space pointer > is valid) first. > > A local attacker can craft a malicious ioctl function call to > > overwrite arbitrary kernel memory, resulting in a Denial of Service or > > privilege escalation (CVE-2018-20669) > > > > This patch makes sure that user_access_begin always does access_ok. > > user_access_begin has been modified to do access_ok internally. > > I had this in the tree, but it broke the build on alpha, sh, and maybe a few > others :( > Thanks Greg for including this patch. I am sorry that this patch caused the failure. As I see this is not a build failure but tests have failed. Build results: total: 155 pass: 155 fail: 0 Qemu test results: total: 421 pass: 390 fail: 31 Failed tests: <all alpha> <all sh> <all sheb> > See: > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F > %2Flore.kernel.org%2Fr%2F20200527140225.GA214763%40roeck- > us.net&data=02%7C01%7Cashwinh%40vmware.com%7Cd8f60bb8a4584 > 7caa10f08d802530997%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7 > C637261902960990057&sdata=Vjv9v0QhebfcOGSq1UUDKshTDA%2FOV > 4aKbqzKKJkEQxM%3D&reserved=0 > for the details. > > Can you dig out all of the needed follow-on patches as well, and send them > all as a patch series for 4.19.y so that I can queue them all up at once? > I will check for follow-on patches and get back. > thanks, > > greg k-h Thanks, Ashwin _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
