mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-16 17:57:38 -04:00
Code Issues Packages Projects Releases Wiki Activity

drm: Do not overrun array in drm_gem_get_pages()

Browse Source 
If the shared memory object is larger than the DRM object that it backs,
we can overrun the page array.  Limit the number of pages we install
from each folio to prevent this.

Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/lkml/13360591.uLZWGnKmhe@natalenko.name/
Fixes: 3291e09a46 ("drm: convert drm_gem_put_pages() to use a folio_batch")
Cc: stable@vger.kernel.org # 6.5.x
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231005135648.2317298-1-willy@infradead.org
This commit is contained in:
Matthew Wilcox (Oracle)
2023-10-05 14:56:47 +01:00
committed by Maxime Ripard
parent 2b7947bd32
commit b7fd68ab15
1 changed files with 4 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/gpu/drm/drm_gem.c
View File

@@ -540,7 +540,7 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
struct page **pages;
struct folio *folio;
struct folio_batch fbatch;
int i, j, npages;
long i, j, npages;
if (WARN_ON(!obj->filp))
return ERR_PTR(-EINVAL);
@@ -564,11 +564,13 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj)
i = 0;
while (i < npages) {
long nr;
folio = shmem_read_folio_gfp(mapping, i,
mapping_gfp_mask(mapping));
if (IS_ERR(folio))
goto fail;
for (j = 0; j < folio_nr_pages(folio); j++, i++)
nr = min(npages - i, folio_nr_pages(folio));
for (j = 0; j < nr; j++, i++)
pages[i] = folio_file_page(folio, i);
/* Make sure shmem keeps __GFP_DMA32 allocated pages in the