commit b86ee2b7ae42b6b37a918b66236608e2cc325f59 Author: Greg Kroah-Hartman Date: Sat Jan 29 10:17:07 2022 +0100 Linux 4.14.264 Link: https://lore.kernel.org/r/20220127180256.764665162@linuxfoundation.org Tested-by: Jon Hunter Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman commit e8d092a62449dcfc73517ca43963d2b8f44d0516 Author: Mathias Krause Date: Thu Jan 27 18:34:19 2022 +1000 drm/vmwgfx: Fix stale file descriptors on failed usercopy commit a0f90c8815706981c483a652a6aefca51a5e191c upstream. A failing usercopy of the fence_rep object will lead to a stale entry in the file descriptor table as put_unused_fd() won't release it. This enables userland to refer to a dangling 'file' object through that still valid file descriptor, leading to all kinds of use-after-free exploitation scenarios. Fix this by deferring the call to fd_install() until after the usercopy has succeeded. Fixes: c906965dee22 ("drm/vmwgfx: Add export fence to file descriptor support") Signed-off-by: Mathias Krause Signed-off-by: Zack Rusin Signed-off-by: Dave Airlie Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman commit 632881680ba0fab07a47157e9db3a029710abbac Author: Ziyang Xuan Date: Sat Jan 22 18:25:06 2022 +0800 can: bcm: fix UAF of bcm op Stopping tasklet and hrtimer rely on the active state of tasklet and hrtimer sequentially in bcm_remove_op(), the op object will be freed if they are all unactive. Assume the hrtimer timeout is short, the hrtimer cb has been excuted after tasklet conditional judgment which must be false after last round tasklet_kill() and before condition hrtimer_active(), it is false when execute to hrtimer_active(). Bug is triggerd, because the stopping action is end and the op object will be freed, but the tasklet is scheduled. The resources of the op object will occur UAF bug. Move hrtimer_cancel() behind tasklet_kill() and switch 'while () {...}' to 'do {...} while ()' to fix the op UAF problem. Fixes: a06393ed0316 ("can: bcm: fix hrtimer/tasklet termination in bcm op removal") Reported-by: syzbot+5ca851459ed04c778d1d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Ziyang Xuan Acked-by: Oliver Hartkopp Signed-off-by: Greg Kroah-Hartman commit eed39c1918f1803948d736c444bfacba2a482ad0 Author: Tvrtko Ursulin Date: Tue Oct 19 13:27:10 2021 +0100 drm/i915: Flush TLBs before releasing backing store commit 7938d61591d33394a21bdd7797a245b65428f44c upstream. We need to flush TLBs before releasing backing store otherwise userspace is able to encounter stale entries if a) it is not declaring access to certain buffers and b) it races with the backing store release from a such undeclared execution already executing on the GPU in parallel. The approach taken is to mark any buffer objects which were ever bound to the GPU and to trigger a serialized TLB flush when their backing store is released. Alternatively the flushing could be done on VMA unbind, at which point we would be able to ascertain whether there is potential a parallel GPU execution (which could race), but essentially it boils down to paying the cost of TLB flushes potentially needlessly at VMA unbind time (when the backing store is not known to be going away so not needed for safety), versus potentially needlessly at backing store relase time (since we at that point cannot tell whether there is anything executing on the GPU which uses that object). Thereforce simplicity of implementation has been chosen for now with scope to benchmark and refine later as required. Signed-off-by: Tvrtko Ursulin Reported-by: Sushma Venkatesh Reddy Reviewed-by: Daniel Vetter Acked-by: Dave Airlie Cc: Daniel Vetter Cc: Jon Bloomfield Cc: Joonas Lahtinen Cc: Jani Nikula Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman