ext4: check for overlapping extents in ext4_valid_extent_entries()

[firefly-linux-kernel-4.4.55.git] / fs / ext4 / extents.c

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 35f65cf4f318d72bce4e79995ddbc85d0e4bbfa3..267c9fb53bf9f0bdbf07d779c6880cb936c8c3fa 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -360,8 +360,10 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
 {
        ext4_fsblk_t block = ext4_ext_pblock(ext);
        int len = ext4_ext_get_actual_len(ext);
+       ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
+       ext4_lblk_t last = lblock + len - 1;
 
-       if (len == 0)
+       if (lblock > last)
                return 0;
        return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
 }
@@ -387,11 +389,26 @@ static int ext4_valid_extent_entries(struct inode *inode,
        if (depth == 0) {
                /* leaf entries */
                struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
+               struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+               ext4_fsblk_t pblock = 0;
+               ext4_lblk_t lblock = 0;
+               ext4_lblk_t prev = 0;
+               int len = 0;
                while (entries) {
                        if (!ext4_valid_extent(inode, ext))
                                return 0;
+
+                       /* Check for overlapping extents */
+                       lblock = le32_to_cpu(ext->ee_block);
+                       len = ext4_ext_get_actual_len(ext);
+                       if ((lblock <= prev) && prev) {
+                               pblock = ext4_ext_pblock(ext);
+                               es->s_last_error_block = cpu_to_le64(pblock);
+                               return 0;
+                       }
                        ext++;
                        entries--;
+                       prev = lblock + len - 1;
                }
        } else {
                struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);