* [PATCH] drm/i915: Fix a crash in shmem_pin_map() error handling
@ 2020-10-23 11:34 Dan Carpenter
[not found] ` <20201023121941.GB18499@lst.de>
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2020-10-23 11:34 UTC (permalink / raw)
To: Jani Nikula, Christoph Hellwig
Cc: Tvrtko Ursulin, David Airlie, intel-gfx, kernel-janitors,
linux-kernel, dri-devel, Chris Wilson, Matthew Auld, Rodrigo Vivi,
Andrew Morton
There is a signedness bug in shmem_pin_map() error handling because "i"
is unsigned. The "while (--i >= 0)" will loop forever until the system
crashes.
Fixes: bfed6708d6c9 ("drm/i915: use vmap in shmem_pin_map")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/gpu/drm/i915/gt/shmem_utils.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
index f011ea42487e..7eb542018219 100644
--- a/drivers/gpu/drm/i915/gt/shmem_utils.c
+++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
@@ -52,8 +52,9 @@ struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
void *shmem_pin_map(struct file *file)
{
struct page **pages;
- size_t n_pages, i;
+ size_t n_pages;
void *vaddr;
+ int i;
n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
--
2.28.0
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] drm/i915: Fix a crash in shmem_pin_map() error handling
[not found] ` <20201023121941.GB18499@lst.de>
@ 2020-10-24 13:47 ` Dan Carpenter
0 siblings, 0 replies; 2+ messages in thread
From: Dan Carpenter @ 2020-10-24 13:47 UTC (permalink / raw)
To: Christoph Hellwig
Cc: dri-devel, Tvrtko Ursulin, David Airlie, intel-gfx,
kernel-janitors, linux-kernel, Chris Wilson, Matthew Auld,
Rodrigo Vivi, Andrew Morton
On Fri, Oct 23, 2020 at 02:19:41PM +0200, Christoph Hellwig wrote:
> > diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
> > index f011ea42487e..7eb542018219 100644
> > --- a/drivers/gpu/drm/i915/gt/shmem_utils.c
> > +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
> > @@ -52,8 +52,9 @@ struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
> > void *shmem_pin_map(struct file *file)
> > {
> > struct page **pages;
> > - size_t n_pages, i;
> > + size_t n_pages;
> > void *vaddr;
> > + int i;
> >
> > n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
> > pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
>
> This assumes we never have more than INT_MAX worth of pages before
> a failure.
Doh. Yeah. My bad.
regards,
dan carpenter
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2020-10-23 11:34 [PATCH] drm/i915: Fix a crash in shmem_pin_map() error handling Dan Carpenter
[not found] ` <20201023121941.GB18499@lst.de>
2020-10-24 13:47 ` Dan Carpenter
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