On 2/18/22 10:35 AM, Felix Kuehling wrote:
Am 2022-02-18 um 12:39 schrieb trix@redhat.com:
From: Tom Rix trix@redhat.com
Clang static analysis reports this problem kfd_chardev.c:2327:2: warning: 1st function call argument is an uninitialized value kvfree(bo_privs); ^~~~~~~~~~~~~~~~
If the copy_from_users(bo_buckets, ...) fails, there is a jump to the generic error handler at exit:. The freeing of bo_privs and unwinding of the dmabuf_fd loop do not need to be done.
Add some specific labels for the early failures. Reorder the frees to be the reverse of their allocs.
Move the initialize of 'i' back to the loop. The problem with the early frees predates the loop unwinding problem.
I think the existing error handling strategy in this function is fine. Having only one exit label avoids potential issues when using the wrong label. Freeing NULL pointers is not a problem. The loop becomes a noop if i==0 (this was fixed by you in a previous patch). The only real problem I see is that bo_privs is not initialized. So this should really be a one-line or maybe two-line fix:
struct kfd_criu_bo_bucket *bo_buckets = NULL; struct kfd_criu_bo_priv_data *bo_privs = NULL;
This is the other way I considered to fix the problem. So it will work.
Tom
Regards, Felix
Fixes: 73fa13b6a511 ("drm/amdkfd: CRIU Implement KFD restore ioctl") Signed-off-by: Tom Rix trix@redhat.com
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 965af2a08bc0..1d5f41ac3832 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -2102,7 +2102,7 @@ static int criu_restore_bos(struct kfd_process *p, const bool criu_resume = true; bool flush_tlbs = false; int ret = 0, j = 0; - uint32_t i = 0; + uint32_t i; if (*priv_offset + (args->num_bos * sizeof(*bo_privs)) > max_priv_data_size) return -EINVAL; @@ -2119,13 +2119,13 @@ static int criu_restore_bos(struct kfd_process *p, if (ret) { pr_err("Failed to copy BOs information from user\n"); ret = -EFAULT; - goto exit; + goto free_buckets; } bo_privs = kvmalloc_array(args->num_bos, sizeof(*bo_privs), GFP_KERNEL); if (!bo_privs) { ret = -ENOMEM; - goto exit; + goto free_buckets; } ret = copy_from_user(bo_privs, (void __user *)args->priv_data
- *priv_offset,
@@ -2133,12 +2133,12 @@ static int criu_restore_bos(struct kfd_process *p, if (ret) { pr_err("Failed to copy BOs information from user\n"); ret = -EFAULT; - goto exit; + goto free_privs; } *priv_offset += args->num_bos * sizeof(*bo_privs); /* Create and map new BOs */ - for (; i < args->num_bos; i++) { + for (i = 0; i < args->num_bos; i++) { struct kfd_criu_bo_bucket *bo_bucket; struct kfd_criu_bo_priv_data *bo_priv; struct kfd_dev *dev; @@ -2323,8 +2323,11 @@ static int criu_restore_bos(struct kfd_process *p, if (bo_buckets[i].alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) close_fd(bo_buckets[i].dmabuf_fd); } - kvfree(bo_buckets); +free_privs: kvfree(bo_privs); +free_buckets: + kvfree(bo_buckets);
return ret; }