* [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
@ 2022-01-24 16:55 ` Zhou Qingyang
0 siblings, 0 replies; 7+ messages in thread
From: Zhou Qingyang @ 2022-01-24 16:55 UTC (permalink / raw)
To: zhou1615
Cc: Mario Kleiner, Leo Li, kjlu, Pan, Xinhui, Rodrigo Siqueira,
linux-kernel, amd-gfx, David Airlie, dri-devel, Daniel Vetter,
Alex Deucher, Lee Jones, Harry Wentland, Christian König
In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
which could lead to a memory leak of yclk.
Fix this bug by changing the location of free_sclk and free_yclk.
This bug was found by a static analyzer.
Builds with 'make allyesconfig' show no new warnings,
and our static analyzer no longer warns about this code.
Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
---
The analysis employs differential checking to identify inconsistent
security operations (e.g., checks or kfrees) between two code paths
and confirms that the inconsistent operations are not recovered in the
current function or the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false
positive or hard to trigger. Multiple researchers have cross-reviewed
the bug.
drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
index ff5bb152ef49..e6ef36de0825 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
@@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
kfree(surface_type);
free_tiling_mode:
kfree(tiling_mode);
-free_yclk:
- kfree(yclk);
free_sclk:
kfree(sclk);
+free_yclk:
+ kfree(yclk);
}
/*******************************************************************************
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
@ 2022-01-24 16:55 ` Zhou Qingyang
0 siblings, 0 replies; 7+ messages in thread
From: Zhou Qingyang @ 2022-01-24 16:55 UTC (permalink / raw)
To: zhou1615
Cc: Leo Li, kjlu, Pan, Xinhui, Rodrigo Siqueira, linux-kernel,
amd-gfx, David Airlie, dri-devel, Alex Deucher, Lee Jones,
Christian König
In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
which could lead to a memory leak of yclk.
Fix this bug by changing the location of free_sclk and free_yclk.
This bug was found by a static analyzer.
Builds with 'make allyesconfig' show no new warnings,
and our static analyzer no longer warns about this code.
Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
---
The analysis employs differential checking to identify inconsistent
security operations (e.g., checks or kfrees) between two code paths
and confirms that the inconsistent operations are not recovered in the
current function or the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false
positive or hard to trigger. Multiple researchers have cross-reviewed
the bug.
drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
index ff5bb152ef49..e6ef36de0825 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
@@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
kfree(surface_type);
free_tiling_mode:
kfree(tiling_mode);
-free_yclk:
- kfree(yclk);
free_sclk:
kfree(sclk);
+free_yclk:
+ kfree(yclk);
}
/*******************************************************************************
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
2022-01-24 16:55 ` Zhou Qingyang
(?)
(?)
@ 2022-01-24 19:19 ` Alex Deucher
-1 siblings, 0 replies; 7+ messages in thread
From: Alex Deucher @ 2022-01-24 19:19 UTC (permalink / raw)
To: Zhou Qingyang
Cc: Leo Li, Kangjie Lu, Pan, Xinhui, Rodrigo Siqueira, LKML,
amd-gfx list, David Airlie, Maling list - DRI developers,
Alex Deucher, Lee Jones, Christian König
Applied. Thanks!
Alex
On Mon, Jan 24, 2022 at 12:05 PM Zhou Qingyang <zhou1615@umn.edu> wrote:
>
> In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
> which could lead to a memory leak of yclk.
>
> Fix this bug by changing the location of free_sclk and free_yclk.
>
> This bug was found by a static analyzer.
>
> Builds with 'make allyesconfig' show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
> The analysis employs differential checking to identify inconsistent
> security operations (e.g., checks or kfrees) between two code paths
> and confirms that the inconsistent operations are not recovered in the
> current function or the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> index ff5bb152ef49..e6ef36de0825 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> @@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
> kfree(surface_type);
> free_tiling_mode:
> kfree(tiling_mode);
> -free_yclk:
> - kfree(yclk);
> free_sclk:
> kfree(sclk);
> +free_yclk:
> + kfree(yclk);
> }
>
> /*******************************************************************************
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
2022-01-24 16:55 ` Zhou Qingyang
(?)
@ 2022-01-28 10:17 ` Greg KH
-1 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2022-01-28 10:17 UTC (permalink / raw)
To: Zhou Qingyang
Cc: kjlu, Harry Wentland, Leo Li, Rodrigo Siqueira, Alex Deucher,
Christian König, Pan, Xinhui, David Airlie, Daniel Vetter,
Lee Jones, Mario Kleiner, amd-gfx, dri-devel, linux-kernel
On Tue, Jan 25, 2022 at 12:55:51AM +0800, Zhou Qingyang wrote:
> In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
> which could lead to a memory leak of yclk.
>
> Fix this bug by changing the location of free_sclk and free_yclk.
>
> This bug was found by a static analyzer.
>
> Builds with 'make allyesconfig' show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
> The analysis employs differential checking to identify inconsistent
> security operations (e.g., checks or kfrees) between two code paths
> and confirms that the inconsistent operations are not recovered in the
> current function or the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> index ff5bb152ef49..e6ef36de0825 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> @@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
> kfree(surface_type);
> free_tiling_mode:
> kfree(tiling_mode);
> -free_yclk:
> - kfree(yclk);
> free_sclk:
> kfree(sclk);
> +free_yclk:
> + kfree(yclk);
> }
>
> /*******************************************************************************
> --
> 2.25.1
>
As stated before, umn.edu is still not allowed to contribute to the
Linux kernel. Please work with your administration to resolve this
issue.
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
@ 2022-01-28 10:17 ` Greg KH
0 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2022-01-28 10:17 UTC (permalink / raw)
To: Zhou Qingyang
Cc: Mario Kleiner, Leo Li, kjlu, Pan, Xinhui, Rodrigo Siqueira,
linux-kernel, amd-gfx, David Airlie, dri-devel, Daniel Vetter,
Alex Deucher, Lee Jones, Harry Wentland, Christian König
On Tue, Jan 25, 2022 at 12:55:51AM +0800, Zhou Qingyang wrote:
> In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
> which could lead to a memory leak of yclk.
>
> Fix this bug by changing the location of free_sclk and free_yclk.
>
> This bug was found by a static analyzer.
>
> Builds with 'make allyesconfig' show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
> The analysis employs differential checking to identify inconsistent
> security operations (e.g., checks or kfrees) between two code paths
> and confirms that the inconsistent operations are not recovered in the
> current function or the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> index ff5bb152ef49..e6ef36de0825 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> @@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
> kfree(surface_type);
> free_tiling_mode:
> kfree(tiling_mode);
> -free_yclk:
> - kfree(yclk);
> free_sclk:
> kfree(sclk);
> +free_yclk:
> + kfree(yclk);
> }
>
> /*******************************************************************************
> --
> 2.25.1
>
As stated before, umn.edu is still not allowed to contribute to the
Linux kernel. Please work with your administration to resolve this
issue.
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] drm/amd/display/dc/calcs/dce_calcs: Fix a memleak in calculate_bandwidth()
@ 2022-01-28 10:17 ` Greg KH
0 siblings, 0 replies; 7+ messages in thread
From: Greg KH @ 2022-01-28 10:17 UTC (permalink / raw)
To: Zhou Qingyang
Cc: Leo Li, kjlu, Pan, Xinhui, Rodrigo Siqueira, linux-kernel,
amd-gfx, David Airlie, dri-devel, Alex Deucher, Lee Jones,
Christian König
On Tue, Jan 25, 2022 at 12:55:51AM +0800, Zhou Qingyang wrote:
> In calculate_bandwidth(), the tag free_sclk and free_yclk are reversed,
> which could lead to a memory leak of yclk.
>
> Fix this bug by changing the location of free_sclk and free_yclk.
>
> This bug was found by a static analyzer.
>
> Builds with 'make allyesconfig' show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: 2be8989d0fc2 ("drm/amd/display/dc/calcs/dce_calcs: Move some large variables from the stack to the heap")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
> The analysis employs differential checking to identify inconsistent
> security operations (e.g., checks or kfrees) between two code paths
> and confirms that the inconsistent operations are not recovered in the
> current function or the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> index ff5bb152ef49..e6ef36de0825 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c
> @@ -2033,10 +2033,10 @@ static void calculate_bandwidth(
> kfree(surface_type);
> free_tiling_mode:
> kfree(tiling_mode);
> -free_yclk:
> - kfree(yclk);
> free_sclk:
> kfree(sclk);
> +free_yclk:
> + kfree(yclk);
> }
>
> /*******************************************************************************
> --
> 2.25.1
>
As stated before, umn.edu is still not allowed to contribute to the
Linux kernel. Please work with your administration to resolve this
issue.
^ permalink raw reply [flat|nested] 7+ messages in thread