Re: [PATCH] drm/amdgpu: prevent BO_HANDLES error from being overwritten

From: Christian König
Date: Wed Oct 09 2024 - 06:34:46 EST


Am 09.10.24 um 10:22 schrieb Pierre-Eric Pelloux-Prayer:
Hi,

Le 05/10/2024 à 01:59, Mohammed Anees a écrit :
Before this patch, if multiple BO_HANDLES chunks were submitted,
the error -EINVAL would be correctly set but could be overwritten
by the return value from amdgpu_cs_p1_bo_handles(). This patch
ensures that once an error condition is detected, the function
returns immediately, avoiding the overwriting of the error code.

Signed-off-by: Mohammed Anees <pvmohammedanees2003@xxxxxxxxx>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 1e475eb01417..543db0df9a31 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -266,8 +266,9 @@ static int amdgpu_cs_pass1(struct amdgpu_cs_parser *p,
              /* Only a single BO list is allowed to simplify handling. */
              if (p->bo_list)
                  ret = -EINVAL;
+            else
+                ret = amdgpu_cs_p1_bo_handles(p, p->chunks[i].kdata);
  -            ret = amdgpu_cs_p1_bo_handles(p, p->chunks[i].kdata);

My bad, I've merged the wrong version of the patch.

That being said, I think it'd be nicer to follow the same pattern as the other checks and do:

   if (p->bo_list)
      goto free_partial_kdata;

Since "ret" is initialized to -EINVAL already.

Also can you add a reference to the broken commit in the commit message?
Something like:

Fixes: fec5f8e8c6bcf83 ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit")

Yeah agree with Pierre-Eric and also please add the same CC stable tag the original patch had so that it gets backported ASAP.

Thanks,
Christian.


Thanks,
Pierre-Eric

              if (ret)
                  goto free_partial_kdata;
              break;