Update 2.6.36 to 2.6.36.4wip-dissipation2-jerickso

1 files changed, 21 insertions, 2 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 8abb2dfb2e7c..4bd454fa844e 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -370,6 +370,9 @@ struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
 {
         struct bio *bio;
 
+        if (nr_iovecs > UIO_MAXIOV)
+                return NULL;
+
         bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
                       gfp_mask);
         if (unlikely(!bio))
@@ -697,8 +700,12 @@ static void bio_free_map_data(struct bio_map_data *bmd)
 static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
                                                gfp_t gfp_mask)
 {
-        struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask);
+        struct bio_map_data *bmd;
 
+        if (iov_count > UIO_MAXIOV)
+                return NULL;
+
+        bmd = kmalloc(sizeof(*bmd), gfp_mask);
         if (!bmd)
                 return NULL;
 
@@ -827,6 +834,12 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
                 end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
                 start = uaddr >> PAGE_SHIFT;
 
+                /*
+                 * Overflow, abort
+                 */
+                if (end < start)
+                        return ERR_PTR(-EINVAL);
+
                 nr_pages += end - start;
                 len += iov[i].iov_len;
         }
@@ -955,6 +968,12 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
                 unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
                 unsigned long start = uaddr >> PAGE_SHIFT;
 
+                /*
+                 * Overflow, abort
+                 */
+                if (end < start)
+                        return ERR_PTR(-EINVAL);
+
                 nr_pages += end - start;
                 /*
                  * buffer must be aligned to at least hardsector size for now
@@ -982,7 +1001,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
                 unsigned long start = uaddr >> PAGE_SHIFT;
                 const int local_nr_pages = end - start;
                 const int page_limit = cur_page + local_nr_pages;
-                
+
                 ret = get_user_pages_fast(uaddr, local_nr_pages,
                                 write_to_vm, &pages[cur_page]);
                 if (ret < local_nr_pages) {