diff options
| author |   Michal Srb <msrb@suse.com> | 2018-02-05 16:04:37 +0000 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-12 19:16:17 +0100 |
| commit | eaae4e6ef12d324a87f82561c570d48e5de98182 (patch) | |
| tree | 18b7e01a950ce3f3656be163b4efc4c7dc37adef /drivers | |
| parent | drm/i915: Prevent writing into a read-only object via a GGTT mmap (diff) | |
| download | linux-stable-eaae4e6ef12d324a87f82561c570d48e5de98182.tar.xz linux-stable-eaae4e6ef12d324a87f82561c570d48e5de98182.zip | |
drm/i915/cmdparser: Check reg_table_count before derefencing.
commit 2f265fad9756a40c09e3f4dcc62d5d7fa73a9fb2 upstream.
The find_reg function was assuming that there is always at least one table in
reg_tables. It is not always true.
In case of VCS or VECS, the reg_tables is NULL and reg_table_count is 0,
implying that no register-accessing commands are allowed. However, the command
tables include commands such as MI_STORE_REGISTER_MEM. When trying to check
such command, the find_reg would dereference NULL pointer.
Now it will just return NULL meaning that the register was not found and the
command will be rejected.
Fixes: 76ff480ec963 ("drm/i915/cmdparser: Use binary search for faster register lookup")
Signed-off-by: Michal Srb <msrb@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205142916.27092-2-msrb@suse.com
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205160438.3267-1-chris@chris-wilson.co.uk
register lookup")
Reviewed-by: Jon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_cmd_parser.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index cd124df3e005..d844ab00be69 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -1038,7 +1038,7 @@ find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr) const struct drm_i915_reg_table *table = engine->reg_tables; int count = engine->reg_table_count; - do { + for (; count > 0; ++table, --count) { if (!table->master || is_master) { const struct drm_i915_reg_descriptor *reg; @@ -1046,7 +1046,7 @@ find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr) if (reg != NULL) return reg; } - } while (table++, --count); + } return NULL; } |