diff options
| author | Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> | 2018-11-09 11:00:12 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-21 09:27:44 +0100 |
| commit | 8ef21c4005bdeb3c7932837abe571d30a1d36ec8 (patch) | |
| tree | d53739d7f6074d8fb25976a9135d6b63c82c6f4c /lib/mpi/mpiutil.c | |
| parent | 67dbeda8f4bb1c728683869ee7c35d50f73e76a3 (diff) | |
drm/dp_mst: Check if primary mstb is null
commit 23d8003907d094f77cf959228e2248d6db819fa7 upstream.
Unfortunately drm_dp_get_mst_branch_device which is called from both
drm_dp_mst_handle_down_rep and drm_dp_mst_handle_up_rep seem to rely
on that mgr->mst_primary is not NULL, which seem to be wrong as it can be
cleared with simultaneous mode set, if probing fails or in other case.
mgr->lock mutex doesn't protect against that as it might just get
assigned to NULL right before, not simultaneously.
There are currently bugs 107738, 108616 bugs which crash in
drm_dp_get_mst_branch_device, caused by this issue.
v2: Refactored the code, as it was nicely noticed.
Fixed Bugzilla bug numbers(second was 108616, but not 108816)
and added links.
[changed title and added stable cc]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108616
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107738
Link: https://patchwork.freedesktop.org/patch/msgid/20181109090012.24438-1-stanislav.lisovskiy@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/mpi/mpiutil.c')
0 files changed, 0 insertions, 0 deletions