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[V3] hw/display/exynos4210_fimd: Fix potential NULL pointer dereference

Message ID 5F9FDBBD.4020607@huawei.com (mailing list archive)
State New, archived
Headers show
Series [V3] hw/display/exynos4210_fimd: Fix potential NULL pointer dereference | expand

Commit Message

Alex Chen Nov. 2, 2020, 10:13 a.m. UTC 
In exynos4210_fimd_update(), the pointer 's' is dereferenced before
checking it is valid, which may lead to NULL pointer dereference.
So move the assignment to global_width after checking 's' is valid.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/display/exynos4210_fimd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Peter Maydell Nov. 2, 2020, 12:02 p.m. UTC | #1 
On Mon, 2 Nov 2020 at 10:13, AlexChen <alex.chen@huawei.com> wrote:
>
> In exynos4210_fimd_update(), the pointer 's' is dereferenced before
> checking it is valid, which may lead to NULL pointer dereference.
> So move the assignment to global_width after checking 's' is valid.
>
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Alex Chen <alex.chen@huawei.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/display/exynos4210_fimd.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)



Applied to target-arm.next, thanks.

-- PMM
diff mbox series

Patch

diff --git a/hw/display/exynos4210_fimd.c b/hw/display/exynos4210_fimd.c
index 4c16e1f5a0..34a960a976 100644
--- a/hw/display/exynos4210_fimd.c
+++ b/hw/display/exynos4210_fimd.c
@@ -1275,12 +1275,14 @@  static void exynos4210_fimd_update(void *opaque)
     bool blend = false;
     uint8_t *host_fb_addr;
     bool is_dirty = false;
-    const int global_width = (s->vidtcon[2] & FIMD_VIDTCON2_SIZE_MASK) + 1;
+    int global_width;

     if (!s || !s->console || !s->enabled ||
         surface_bits_per_pixel(qemu_console_surface(s->console)) == 0) {
         return;
     }
+
+    global_width = (s->vidtcon[2] & FIMD_VIDTCON2_SIZE_MASK) + 1;
     exynos4210_update_resolution(s);
     surface = qemu_console_surface(s->console);