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SubjectRE: [PATCH] drm/amdgpu: Fix realloc of ptr
Date
From: trix@redhat.com
> Sent: 26 February 2022 15:59
>
> From: Tom Rix <trix@redhat.com>
>
> Clang static analysis reports this error
> amdgpu_debugfs.c:1690:9: warning: 1st function call
> argument is an uninitialized value
> tmp = krealloc_array(tmp, i + 1,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> realloc will free tmp, so tmp can not be garbage.
> And the return needs to be checked.

Are you sure?
A quick check seems to show that krealloc() behaves the same
way as libc realloc() and the pointer isn't freed on failure.

David

> Fixes: 5ce5a584cb82 ("drm/amdgpu: add debugfs for reset registers list")
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 9eb9b440bd438..159b97c0b4ebc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1676,7 +1676,7 @@ static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
> {
> struct amdgpu_device *adev = (struct amdgpu_device *)file_inode(f)->i_private;
> char reg_offset[11];
> - uint32_t *tmp;
> + uint32_t *tmp = NULL;
> int ret, i = 0, len = 0;
>
> do {
> @@ -1688,6 +1688,10 @@ static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
> }
>
> tmp = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);
> + if (!tmp) {
> + ret = -ENOMEM;
> + goto error_free;
> + }
> if (sscanf(reg_offset, "%X %n", &tmp[i], &ret) != 1) {
> ret = -EINVAL;
> goto error_free;
> --
> 2.26.3

-
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