| Message ID | 20180911065921.23818-8-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | udmabuf: misc fixes. | expand |
Hi Gerd, Thank you for the patch. On Tuesday, 11 September 2018 09:59:18 EEST Gerd Hoffmann wrote: > Create variable for the list length limit. Serves as documentation, > also allows to make it a module parameter if needed. > > Also add a total size limit. > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> > --- > drivers/dma-buf/udmabuf.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c > index 0cf7e85585..cb99a7886a 100644 > --- a/drivers/dma-buf/udmabuf.c > +++ b/drivers/dma-buf/udmabuf.c > @@ -12,6 +12,9 @@ > #include <linux/shmem_fs.h> > #include <linux/udmabuf.h> > > +static int list_limit = 1024; /* udmabuf_create_list->count limit */ > +static int size_limit_mb = 64; /* total dmabuf size, in megabytes */ static const int maybe ? Or size_t for the size limit and unsigned int for the limit on the number of entries, as they can't be negative ? Why those specific values ? > struct udmabuf { > pgoff_t pagecount; > struct page **pages; > @@ -123,7 +126,7 @@ static long udmabuf_create(struct const > udmabuf_create_list *head, struct file *memfd = NULL; > struct udmabuf *ubuf; > struct dma_buf *buf; > - pgoff_t pgoff, pgcnt, pgidx, pgbuf; > + pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit; > struct page *page; > int seals, ret = -EINVAL; > u32 i, flags; > @@ -132,12 +135,15 @@ static long udmabuf_create(struct const > udmabuf_create_list *head, if (!ubuf) > return -ENOMEM; > > + pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT; > for (i = 0; i < head->count; i++) { > if (!IS_ALIGNED(list[i].offset, PAGE_SIZE)) > goto err_free_ubuf; > if (!IS_ALIGNED(list[i].size, PAGE_SIZE)) > goto err_free_ubuf; > ubuf->pagecount += list[i].size >> PAGE_SHIFT; > + if (ubuf->pagecount > pglimit) > + goto err_free_ubuf; > } > ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *), > GFP_KERNEL); > @@ -227,7 +233,7 @@ static long udmabuf_ioctl_create_list(struct file *filp, > unsigned long arg) > > if (copy_from_user(&head, (void __user *)arg, sizeof(head))) > return -EFAULT; > - if (head.count > 1024) > + if (head.count > list_limit) > return -EINVAL; > lsize = sizeof(struct udmabuf_create_item) * head.count; > list = memdup_user((void __user *)(arg + sizeof(head)), lsize);
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 0cf7e85585..cb99a7886a 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -12,6 +12,9 @@ #include <linux/shmem_fs.h> #include <linux/udmabuf.h> +static int list_limit = 1024; /* udmabuf_create_list->count limit */ +static int size_limit_mb = 64; /* total dmabuf size, in megabytes */ + struct udmabuf { pgoff_t pagecount; struct page **pages; @@ -123,7 +126,7 @@ static long udmabuf_create(struct const udmabuf_create_list *head, struct file *memfd = NULL; struct udmabuf *ubuf; struct dma_buf *buf; - pgoff_t pgoff, pgcnt, pgidx, pgbuf; + pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit; struct page *page; int seals, ret = -EINVAL; u32 i, flags; @@ -132,12 +135,15 @@ static long udmabuf_create(struct const udmabuf_create_list *head, if (!ubuf) return -ENOMEM; + pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT; for (i = 0; i < head->count; i++) { if (!IS_ALIGNED(list[i].offset, PAGE_SIZE)) goto err_free_ubuf; if (!IS_ALIGNED(list[i].size, PAGE_SIZE)) goto err_free_ubuf; ubuf->pagecount += list[i].size >> PAGE_SHIFT; + if (ubuf->pagecount > pglimit) + goto err_free_ubuf; } ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *), GFP_KERNEL); @@ -227,7 +233,7 @@ static long udmabuf_ioctl_create_list(struct file *filp, unsigned long arg) if (copy_from_user(&head, (void __user *)arg, sizeof(head))) return -EFAULT; - if (head.count > 1024) + if (head.count > list_limit) return -EINVAL; lsize = sizeof(struct udmabuf_create_item) * head.count; list = memdup_user((void __user *)(arg + sizeof(head)), lsize);
Create variable for the list length limit. Serves as documentation, also allows to make it a module parameter if needed. Also add a total size limit. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- drivers/dma-buf/udmabuf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)