In Linux 4.3-rc5, there is an error case in drm_dp_get_branch_device that returns without releasing mgr->lock, resulting a spew of kernel messages about a kernel work function possibly having leaked a mutex and presumably more serious adverse consequences later. This patch changes the error to "goto out" to unlock the mutex before returning.
Signed-off-by: Adam J. Richter adam_richter2004@yahoo.com ---
bugzilla.freedesktop.org ticket: https://bugs.freedesktop.org/show_bug.cgi?id=92480
This patch is against the latest git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git . I apologize in advance in I should be submitting patches against some other reference. Please feel free to let me know if I should use some other reference for submitting future patches.
My request to subscribe to dri-devel@lists.freedesktop.org is pending, so I apologize if it takes a while for this message to be posted on the mailing list.
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07..018ad7f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1194,17 +1194,18 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) { - if (!port->mstb) { + mstb = port->mstb; + if (!mstb) { DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]); - return NULL; + goto out; }
- mstb = port->mstb; break; } } } kref_get(&mstb->kref); + out: mutex_unlock(&mgr->lock); return mstb; }
On Fri, Oct 16, 2015 at 03:33:02AM -0700, Adam Richter wrote:
In Linux 4.3-rc5, there is an error case in drm_dp_get_branch_device that returns without releasing mgr->lock, resulting a spew of kernel messages about a kernel work function possibly having leaked a mutex and presumably more serious adverse consequences later. This patch changes the error to "goto out" to unlock the mutex before returning.
Signed-off-by: Adam J. Richter adam_richter2004@yahoo.com
Patch was whitespace mangled (don't past them into your mailer but instead send them with git send-email directly, that's safer), so I had to recreate it.
Applied to drm-misc, thanks. -Daniel
bugzilla.freedesktop.org ticket: https://bugs.freedesktop.org/show_bug.cgi?id=92480
This patch is against the latest git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git . I apologize in advance in I should be submitting patches against some other reference. Please feel free to let me know if I should use some other reference for submitting future patches.
My request to subscribe to dri-devel@lists.freedesktop.org is pending, so I apologize if it takes a while for this message to be posted on the mailing list.
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07..018ad7f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1194,17 +1194,18 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) {
if (!port->mstb) {
mstb = port->mstb;if (!mstb) { DRM_ERROR("failed to lookupMSTB with lct %d, rad %02x\n", lct, rad[0]);
return NULL;
goto out; }
mstb = port->mstb; break; } } } kref_get(&mstb->kref);
- out: mutex_unlock(&mgr->lock); return mstb;
} _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi, Daniel.
Thank you for your quick handling of my patch submission.
I will look into setting up git send-email.
Adam
On Fri, Oct 16, 2015 at 10:24 AM, Daniel Vetter daniel@ffwll.ch wrote:
On Fri, Oct 16, 2015 at 03:33:02AM -0700, Adam Richter wrote:
In Linux 4.3-rc5, there is an error case in drm_dp_get_branch_device that returns without releasing mgr->lock, resulting a spew of kernel messages about a kernel work function possibly having leaked a mutex and presumably more serious adverse consequences later. This patch changes the error to "goto out" to unlock the mutex before returning.
Signed-off-by: Adam J. Richter adam_richter2004@yahoo.com
Patch was whitespace mangled (don't past them into your mailer but instead send them with git send-email directly, that's safer), so I had to recreate it.
Applied to drm-misc, thanks. -Daniel
bugzilla.freedesktop.org ticket: https://bugs.freedesktop.org/show_bug.cgi?id=92480
This patch is against the latest git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git . I apologize in advance in I should be submitting patches against some other reference. Please feel free to let me know if I should use some other reference for submitting future patches.
My request to subscribe to dri-devel@lists.freedesktop.org is pending, so I apologize if it takes a while for this message to be posted on the mailing list.
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07..018ad7f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1194,17 +1194,18 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) {
if (!port->mstb) {
mstb = port->mstb;if (!mstb) { DRM_ERROR("failed to lookupMSTB with lct %d, rad %02x\n", lct, rad[0]);
return NULL;
goto out; }
mstb = port->mstb; break; } } } kref_get(&mstb->kref);
- out: mutex_unlock(&mgr->lock); return mstb;
} _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
On Fri, 16 Oct 2015, Daniel Vetter daniel@ffwll.ch wrote:
On Fri, Oct 16, 2015 at 03:33:02AM -0700, Adam Richter wrote:
In Linux 4.3-rc5, there is an error case in drm_dp_get_branch_device that returns without releasing mgr->lock, resulting a spew of kernel messages about a kernel work function possibly having leaked a mutex and presumably more serious adverse consequences later. This patch changes the error to "goto out" to unlock the mutex before returning.
Signed-off-by: Adam J. Richter adam_richter2004@yahoo.com
Patch was whitespace mangled (don't past them into your mailer but instead send them with git send-email directly, that's safer), so I had to recreate it.
Applied to drm-misc, thanks.
It's missing
Reviewed-by: Jani Nikula jani.nikula@intel.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92480 Fixes: 9eb1e57f564d ("drm/dp/mst: take lock around looking up the branch device on hpd irq") Cc: stable@vger.kernel.org # v4.2+
and arguably was for drm-fixes.
BR, Jani.
-Daniel
bugzilla.freedesktop.org ticket: https://bugs.freedesktop.org/show_bug.cgi?id=92480
This patch is against the latest git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git . I apologize in advance in I should be submitting patches against some other reference. Please feel free to let me know if I should use some other reference for submitting future patches.
My request to subscribe to dri-devel@lists.freedesktop.org is pending, so I apologize if it takes a while for this message to be posted on the mailing list.
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bf27a07..018ad7f 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1194,17 +1194,18 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) {
if (!port->mstb) {
mstb = port->mstb;if (!mstb) { DRM_ERROR("failed to lookupMSTB with lct %d, rad %02x\n", lct, rad[0]);
return NULL;
goto out; }
mstb = port->mstb; break; } } } kref_get(&mstb->kref);
- out: mutex_unlock(&mgr->lock); return mstb;
} _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
dri-devel@lists.freedesktop.org
-
Adam Richter -
Daniel Vetter -
Jani Nikula