commit f4b1bd6d9c2e2818ad1ef2483471c8b9a5c0a01c
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sat Jan 29 10:19:19 2022 +0100
Linux 4.19.227
Link: https://lore.kernel.org/r/20220127180256.837257619@linuxfoundation.org
Tested-by: Pavel Machek (CIP) <pavel@denx.de>
Tested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0008a0c78fc33a84e2212a7c04e6b21a36ca6f4d
Author: Mathias Krause <minipli@grsecurity.net>
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 <minipli@grsecurity.net>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6717900f775a6129a7b4d03ba4922218d8bf1caa
Author: Jan Kara <jack@suse.cz>
Date: Mon Jan 10 19:19:23 2022 +0100
select: Fix indefinitely sleeping task in poll_schedule_timeout()
commit 68514dacf2715d11b91ca50d88de047c086fea9c upstream.
A task can end up indefinitely sleeping in do_select() ->
poll_schedule_timeout() when the following race happens:
TASK1 (thread1) TASK2 TASK1 (thread2)
do_select()
setup poll_wqueues table
with 'fd'
write data to 'fd'
pollwake()
table->triggered = 1
closes 'fd' thread1 is
waiting for
poll_schedule_timeout()
- sees table->triggered
table->triggered = 0
return -EINTR
loop back in do_select()
But at this point when TASK1 loops back, the fdget() in the setup of
poll_wqueues fails. So now so we never find 'fd' is ready for reading
and sleep in poll_schedule_timeout() indefinitely.
Treat an fd that got closed as a fd on which some event happened. This
makes sure cannot block indefinitely in do_select().
Another option would be to return -EBADF in this case but that has a
potential of subtly breaking applications that excercise this behavior
and it happens to work for them. So returning fd as active seems like a
safer choice.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ac06e167c4ae08e481c7944677856c638724643a
Author: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Fri Jul 31 19:26:16 2020 +0300
net: bridge: clear bridge's private skb space on xmit
commit fd65e5a95d08389444e8591a20538b3edece0e15 upstream.
We need to clear all of the bridge private skb variables as they can be
stale due to the packet being recirculated through the stack and then
transmitted through the bridge device. Similar memset is already done on
bridge's input. We've seen cases where proxyarp_replied was 1 on routed
multicast packets transmitted through the bridge to ports with neigh
suppress which were getting dropped. Same thing can in theory happen with
the port isolation bit as well.
Fixes: 821f1b21cabb ("bridge: add new BR_NEIGH_SUPPRESS port flag to suppress arp and nd flood")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Huang Guobin <huangguobin4@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b188780649081782e341e52223db47c49f172712
Author: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
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 <tvrtko.ursulin@intel.com>
Reported-by: Sushma Venkatesh Reddy <sushma.venkatesh.reddy@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>