The cleanup tail of kfd_criu_resume_svm() walks
svms->criu_svm_metadata_list and kfree()s each struct criu_svm_metadata
without removing it from the list. The list head is left pointing at
freed kmalloc-96 objects.
A second AMDKFD_IOC_CRIU_OP from the same process re-enters: list_empty()
reads the dangling ->next (use-after-free), the loop walks freed entries,
and each is kfree()'d again (double-free). This is reachable by an
unprivileged render-group user via /dev/kfd with no capabilities required.
Add list_del() before the kfree() so the list is properly emptied. The
list_for_each_entry_safe() iterator already caches the next pointer, so
unlinking during the walk is safe.
Fixes: 2a909ae71871 ("drm/amdkfd: CRIU resume shared virtual memory ranges")
Signed-off-by: Mario Limonciello <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 8d241ad760f19..df7fca65e9a21 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -4115,6 +4115,7 @@ int kfd_criu_resume_svm(struct kfd_process *p)
list_for_each_entry_safe(criu_svm_md, next,
&svms->criu_svm_metadata_list, list) {
pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
criu_svm_md->data.start_addr);
+ list_del(&criu_svm_md->list);
kfree(criu_svm_md);
}
--
2.43.0
