| Message ID | 20241211043252.3295947-1-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] vmalloc: Fix accounting of VmallocUsed with i915 | expand |
On Wed, Dec 11, 2024 at 04:32:49AM +0000, Matthew Wilcox (Oracle) wrote: > If the caller of vmap() specifies VM_MAP_PUT_PAGES (currently only the > i915 driver), we will decrement nr_vmalloc_pages in vfree() without ever > incrementing it. Check the flag before decrementing the counter. > > Fixes: b944afc9d64d (mm: add a VM_MAP_PUT_PAGES flag for vmap) > Cc: stable@vger.kernel.org > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
On Wed, Dec 11, 2024 at 04:32:49AM +0000, Matthew Wilcox (Oracle) wrote: > If the caller of vmap() specifies VM_MAP_PUT_PAGES (currently only the > i915 driver), we will decrement nr_vmalloc_pages in vfree() without ever > incrementing it. Check the flag before decrementing the counter. > > Fixes: b944afc9d64d (mm: add a VM_MAP_PUT_PAGES flag for vmap) > Cc: stable@vger.kernel.org > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f009b21705c1..bc9c91f3b373 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3382,7 +3382,8 @@ void vfree(const void *addr) __free_page(page); cond_resched(); } - atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); + if (!(vm->flags & VM_MAP_PUT_PAGES)) + atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); kvfree(vm->pages); kfree(vm); }
If the caller of vmap() specifies VM_MAP_PUT_PAGES (currently only the i915 driver), we will decrement nr_vmalloc_pages in vfree() without ever incrementing it. Check the flag before decrementing the counter. Fixes: b944afc9d64d (mm: add a VM_MAP_PUT_PAGES flag for vmap) Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/vmalloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)