diff options
| author | Michal Srb <msrb@suse.com> | 2018-02-05 19:04:38 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-10-21 10:44:46 +0300 |
| commit | 288aba7ed19bc8b39de19f564dbd4bde97332c3c (patch) | |
| tree | db846785560541b62ad83644518da70d179dc3c9 /drivers/gpu/drm | |
| parent | c166be1b3aea6eaa9c167656b53c018aa1a9089e (diff) | |
| download | linux-288aba7ed19bc8b39de19f564dbd4bde97332c3c.tar.xz | |
drm/i915/cmdparser: Do not check past the cmd length.
commit 3aec7f871c65eb5f76b4125fda432593c834a6f2 upstream.
The command MEDIA_VFE_STATE checks bits at offset +2 dwords. However, it is
possible to have MEDIA_VFE_STATE command with length = 0 + LENGTH_BIAS = 2.
In that case check_cmd will read bits from the following command, or even past
the end of the buffer.
If the offset ends up outside of the command length, reject the command.
Fixes: 351e3db2b363 ("drm/i915: Implement command buffer parsing logic")
Signed-off-by: Michal Srb <msrb@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205151745.29292-1-msrb@suse.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/20180205160438.3267-2-chris@chris-wilson.co.uk
[bwh: Backported to 3.16: Log ring->id rather than engine->name]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_cmd_parser.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index d9740532a4a8..df9512ef1280 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -941,6 +941,12 @@ static bool check_cmd(const struct intel_engine_cs *ring, continue; } + if (desc->bits[i].offset >= length) { + DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X, too short to check bitmask (ring=%d)\n", + *cmd, ring->id); + return false; + } + dword = cmd[desc->bits[i].offset] & desc->bits[i].mask; |