[PATCH] drm/nouveau: fix reversed error cleanup order in ucopy functions

[Junrui Luo]

nouveau_uvmm_vm_bind_ucopy() and nouveau_exec_ucopy() place their error
cleanup labels in allocation order rather than reverse allocation order.
On a u_memcpya() failure for in_sync.s, the goto to err_free_ops (or
err_free_pushs) frees the first allocation and then falls through to
err_free_ins, which calls u_free() on args->in_sync.s.

Since args->in_sync.s still holds the ERR_PTR returned by the failed
u_memcpya(), and ERR_PTR values are not caught by ZERO_OR_NULL_PTR(),
kvfree() proceeds to dereference it, which can result in a kernel oops.
A failure for out_sync.s instead jumps to err_free_ins and skips freeing
the first allocation, leading to a memory leak.

Fix by swapping the cleanup label order so resources are freed in the
correct reverse allocation sequence.

Fixes: b88baab82871 ("drm/nouveau: implement new VM_BIND uAPI")
Reported-by: Yuhao Jiang <danisjiang@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Junrui Luo <moonafterrain@xxxxxxxxxxx>
---
 drivers/gpu/drm/nouveau/nouveau_exec.c | 4 ++--
 drivers/gpu/drm/nouveau/nouveau_uvmm.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_exec.c b/drivers/gpu/drm/nouveau/nouveau_exec.c
index c01a01aee32b..a08ab1cfea9b 100644
--- a/drivers/gpu/drm/nouveau/nouveau_exec.c
+++ b/drivers/gpu/drm/nouveau/nouveau_exec.c
@@ -331,10 +331,10 @@ nouveau_exec_ucopy(struct nouveau_exec_job_args *args,
 
 	return 0;
 
-err_free_pushs:
-	u_free(args->push.s);
 err_free_ins:
 	u_free(args->in_sync.s);
+err_free_pushs:
+	u_free(args->push.s);
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
index 36445915aa58..f5e4756b4de4 100644
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
@@ -1779,10 +1779,10 @@ nouveau_uvmm_vm_bind_ucopy(struct nouveau_uvmm_bind_job_args *args,
 
 	return 0;
 
-err_free_ops:
-	u_free(args->op.s);
 err_free_ins:
 	u_free(args->in_sync.s);
+err_free_ops:
+	u_free(args->op.s);
 	return ret;
 }
 

---
base-commit: ddd664bbff63e09e7a7f9acae9c43605d4cf185f
change-id: 20260608-fixes-cb491288eb71

Best regards,
-- 
Junrui Luo <moonafterrain@xxxxxxxxxxx>