| From d18c96032dd9f2ce8fc58130cd8e372aa715ffe6 Mon Sep 17 00:00:00 2001 |
| From: "Darrick J. Wong" <darrick.wong@oracle.com> |
| Date: Mon, 5 Dec 2016 12:38:38 +1100 |
| Subject: [PATCH] xfs: don't allow di_size with high bit set |
| |
| commit ef388e2054feedaeb05399ed654bdb06f385d294 upstream. |
| |
| The on-disk field di_size is used to set i_size, which is a signed |
| integer of loff_t. If the high bit of di_size is set, we'll end up with |
| a negative i_size, which will cause all sorts of problems. Since the |
| VFS won't let us create a file with such length, we should catch them |
| here in the verifier too. |
| |
| Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> |
| Reviewed-by: Dave Chinner <dchinner@redhat.com> |
| Signed-off-by: Dave Chinner <david@fromorbit.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c |
| index 4b9769e23c83..46debfa50a0f 100644 |
| --- a/fs/xfs/libxfs/xfs_inode_buf.c |
| +++ b/fs/xfs/libxfs/xfs_inode_buf.c |
| @@ -376,6 +376,14 @@ xfs_dinode_verify( |
| if (dip->di_magic != cpu_to_be16(XFS_DINODE_MAGIC)) |
| return false; |
| |
| + /* don't allow invalid i_size */ |
| + if (be64_to_cpu(dip->di_size) & (1ULL << 63)) |
| + return false; |
| + |
| + /* No zero-length symlinks. */ |
| + if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0) |
| + return false; |
| + |
| /* only version 3 or greater inodes are extensively verified here */ |
| if (dip->di_version < 3) |
| return true; |
| -- |
| 2.10.1 |
| |
