Fix a double free and an uninitialized pointer read error. Both tmp and
new are pointing at same address and both are freed which leads to
double free. Adding a check to verify if new and tmp are free in the
error_free label fixes the double free issue. new is not initialized to
null which also leads to a free on an uninitialized pointer.
Suggested by: S. Amaranath <[email protected]>
Signed-off-by: Sebin Sebastian <[email protected]>
---
Changes in v2:
Updated patch body as suggested by André Almeida <[email protected]>
Reworked to implement a check in error_free for fixing double free error
as suggested by S. Amaranath <[email protected]>
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index e2eec985adb3..cb00c7d6f50b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1705,7 +1705,7 @@ 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 *new, *tmp = NULL;
+ uint32_t *new = NULL, *tmp = NULL;
int ret, i = 0, len = 0;
do {
@@ -1747,7 +1747,8 @@ static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
ret = size;
error_free:
- kfree(tmp);
+ if (tmp != new)
+ kfree(tmp);
kfree(new);
return ret;
}
--
2.34.1
[AMD Official Use Only - General]
Reviewed-by: Evan Quan <[email protected]>
> -----Original Message-----
> From: Sebin Sebastian <[email protected]>
> Sent: Saturday, July 30, 2022 11:47 AM
> Cc: [email protected]; Deucher, Alexander
> <[email protected]>; Koenig, Christian
> <[email protected]>; Pan, Xinhui <[email protected]>; David
> Airlie <[email protected]>; Daniel Vetter <[email protected]>; Nirmoy Das
> <[email protected]>; Lazar, Lijo <[email protected]>; Quan, Evan
> <[email protected]>; StDenis, Tom <[email protected]>;
> Somalapuram, Amaranath <[email protected]>; André
> Almeida <[email protected]>; [email protected]; dri-
> [email protected]; [email protected]
> Subject: [PATCHv2 -next] drm/amdgpu: double free error and freeing
> uninitialized null pointer
>
> Fix a double free and an uninitialized pointer read error. Both tmp and
> new are pointing at same address and both are freed which leads to
> double free. Adding a check to verify if new and tmp are free in the
> error_free label fixes the double free issue. new is not initialized to
> null which also leads to a free on an uninitialized pointer.
>
> Suggested by: S. Amaranath <[email protected]>
> Signed-off-by: Sebin Sebastian <[email protected]>
> ---
> Changes in v2:
> Updated patch body as suggested by André Almeida
> <[email protected]>
> Reworked to implement a check in error_free for fixing double free error
> as suggested by S. Amaranath <[email protected]>
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index e2eec985adb3..cb00c7d6f50b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -1705,7 +1705,7 @@ 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 *new, *tmp = NULL;
> + uint32_t *new = NULL, *tmp = NULL;
> int ret, i = 0, len = 0;
>
> do {
> @@ -1747,7 +1747,8 @@ static ssize_t
> amdgpu_reset_dump_register_list_write(struct file *f,
> ret = size;
>
> error_free:
> - kfree(tmp);
> + if (tmp != new)
> + kfree(tmp);
> kfree(new);
> return ret;
> }
> --
> 2.34.1
Às 00:46 de 30/07/22, Sebin Sebastian escreveu:
> Fix a double free and an uninitialized pointer read error. Both tmp and
> new are pointing at same address and both are freed which leads to
> double free. Adding a check to verify if new and tmp are free in the
> error_free label fixes the double free issue. new is not initialized to
> null which also leads to a free on an uninitialized pointer.
>
> Suggested by: S. Amaranath <[email protected]>
> Signed-off-by: Sebin Sebastian <[email protected]>
Reviewed-by: André Almeida <[email protected]>
Applied. Thanks!
Alex
On Mon, Aug 1, 2022 at 1:08 PM André Almeida <[email protected]> wrote:
>
> Às 00:46 de 30/07/22, Sebin Sebastian escreveu:
> > Fix a double free and an uninitialized pointer read error. Both tmp and
> > new are pointing at same address and both are freed which leads to
> > double free. Adding a check to verify if new and tmp are free in the
> > error_free label fixes the double free issue. new is not initialized to
> > null which also leads to a free on an uninitialized pointer.
> >
> > Suggested by: S. Amaranath <[email protected]>
> > Signed-off-by: Sebin Sebastian <[email protected]>
>
> Reviewed-by: André Almeida <[email protected]>