commit e582951baabba3e278c97169d0acc1e09b24a72e upstream.
To avoid any possible use after free.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/414814/
CC: stable@vger.kernel.org
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 135517d3565b48f4def3b1b82008bc17eb5d1c90 ]
Problem:
Due to a race between drm_sched_cleanup_jobs in sched thread and
drm_sched_job_timedout in timeout work there is a possiblity that
bad job was already freed while still being accessed from the
timeout thread.
Fix:
Instead of just peeking at the bad job in the mirror list
remove it from the list under lock and then put it back later when
we are garanteed no race with main sched thread is possible which
is after the thread is parked.
v2: Lock around processing ring_mirror_list in drm_sched_cleanup_jobs.
v3: Rebase on top of drm-misc-next. v2 is not needed anymore as
drm_sched_get_cleanup_job already has a lock there.
v4: Fix comments to relfect latest code in drm-misc.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Emily Deng <Emily.Deng@amd.com>
Tested-by: Emily Deng <Emily.Deng@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/342356
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 77bb2f204f1f0a53a602a8fd15816d6826212077 ]
There is one one corner case at dma_fence_signal_locked
which will raise the NULL pointer problem just like below.
->dma_fence_signal
->dma_fence_signal_locked
->test_and_set_bit
here trigger dma_fence_release happen due to the zero of fence refcount.
->dma_fence_put
->dma_fence_release
->drm_sched_fence_release_scheduled
->call_rcu
here make the union fled “cb_list” at finished fence
to NULL because struct rcu_head contains two pointer
which is same as struct list_head cb_list
Therefore, to hold the reference of finished fence at drm_sched_process_job
to prevent the null pointer during finished fence dma_fence_signal
[ 732.912867] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 732.914815] #PF: supervisor write access in kernel mode
[ 732.915731] #PF: error_code(0x0002) - not-present page
[ 732.916621] PGD 0 P4D 0
[ 732.917072] Oops: 0002 [#1] SMP PTI
[ 732.917682] CPU: 7 PID: 0 Comm: swapper/7 Tainted: G OE 5.4.0-rc7 #1
[ 732.918980] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014
[ 732.920906] RIP: 0010:dma_fence_signal_locked+0x3e/0x100
[ 732.938569] Call Trace:
[ 732.939003] <IRQ>
[ 732.939364] dma_fence_signal+0x29/0x50
[ 732.940036] drm_sched_fence_finished+0x12/0x20 [gpu_sched]
[ 732.940996] drm_sched_process_job+0x34/0xa0 [gpu_sched]
[ 732.941910] dma_fence_signal_locked+0x85/0x100
[ 732.942692] dma_fence_signal+0x29/0x50
[ 732.943457] amdgpu_fence_process+0x99/0x120 [amdgpu]
[ 732.944393] sdma_v4_0_process_trap_irq+0x81/0xa0 [amdgpu]
v2: hold the finished fence at drm_sched_process_job instead of
amdgpu_fence_process
v3: resume the blank line
Signed-off-by: Yintian Tao <yttao@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Andrey Grodzovsky