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authorLinus Torvalds <torvalds@linux-foundation.org>2018-03-22 18:48:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-03-22 18:48:43 -0700
commitf36b7534b83357cf52e747905de6d65b4f7c2512 (patch)
treeca52ebdc4aaa738bd464b22a06ed034e41c46acb /fs
parent8401c72c593d2be8607d2a0a4551ee5c867d6f2f (diff)
parent9d3c3354bb85bab4d865fe95039443f09a4c8394 (diff)
downloadlinux-f36b7534b83357cf52e747905de6d65b4f7c2512.tar.bz2
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton: "13 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, thp: do not cause memcg oom for thp mm/vmscan: wake up flushers for legacy cgroups too Revert "mm: page_alloc: skip over regions of invalid pfns where possible" mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink() mm/thp: do not wait for lock_page() in deferred_split_scan() mm/khugepaged.c: convert VM_BUG_ON() to collapse fail x86/mm: implement free pmd/pte page interfaces mm/vmalloc: add interfaces to free unmapped page table h8300: remove extraneous __BIG_ENDIAN definition hugetlbfs: check for pgoff value overflow lockdep: fix fs_reclaim warning MAINTAINERS: update Mark Fasheh's e-mail mm/mempolicy.c: avoid use uninitialized preferred_node
Diffstat (limited to 'fs')
-rw-r--r--fs/hugetlbfs/inode.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 8fe1b0aa2896..b9a254dcc0e7 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -108,6 +108,16 @@ static void huge_pagevec_release(struct pagevec *pvec)
pagevec_reinit(pvec);
}
+/*
+ * Mask used when checking the page offset value passed in via system
+ * calls. This value will be converted to a loff_t which is signed.
+ * Therefore, we want to check the upper PAGE_SHIFT + 1 bits of the
+ * value. The extra bit (- 1 in the shift value) is to take the sign
+ * bit into account.
+ */
+#define PGOFF_LOFFT_MAX \
+ (((1UL << (PAGE_SHIFT + 1)) - 1) << (BITS_PER_LONG - (PAGE_SHIFT + 1)))
+
static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file_inode(file);
@@ -127,12 +137,13 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
vma->vm_ops = &hugetlb_vm_ops;
/*
- * Offset passed to mmap (before page shift) could have been
- * negative when represented as a (l)off_t.
+ * page based offset in vm_pgoff could be sufficiently large to
+ * overflow a (l)off_t when converted to byte offset.
*/
- if (((loff_t)vma->vm_pgoff << PAGE_SHIFT) < 0)
+ if (vma->vm_pgoff & PGOFF_LOFFT_MAX)
return -EINVAL;
+ /* must be huge page aligned */
if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
return -EINVAL;