[RAMEN9610-20751]ext4: zero out the unused memory region in the extent tree block

[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / fs / ext4 / extents.c

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5592b7726241793b4f19c737ed42087ba57959ed..01f44364c547ed749fd8960423a97bf16d4a53f8 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1047,6 +1047,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        __le32 border;
        ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
        int err = 0;
+       size_t ext_size = 0;
 
        /* make decision: where to split? */
        /* FIXME: now decision is simplest: at current extent */
@@ -1138,6 +1139,10 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                le16_add_cpu(&neh->eh_entries, m);
        }
 
+       /* zero out unused area in the extent block */
+       ext_size = sizeof(struct ext4_extent_header) +
+               sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
+       memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
        ext4_extent_block_csum_set(inode, neh);
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
@@ -1217,6 +1222,11 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                                sizeof(struct ext4_extent_idx) * m);
                        le16_add_cpu(&neh->eh_entries, m);
                }
+               /* zero out unused area in the extent block */
+               ext_size = sizeof(struct ext4_extent_header) +
+                  (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
+               memset(bh->b_data + ext_size, 0,
+                       inode->i_sb->s_blocksize - ext_size);
                ext4_extent_block_csum_set(inode, neh);
                set_buffer_uptodate(bh);
                unlock_buffer(bh);
@@ -1282,6 +1292,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        ext4_fsblk_t newblock, goal = 0;
        struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
        int err = 0;
+       size_t ext_size = 0;
 
        /* Try to prepend new index to old one */
        if (ext_depth(inode))
@@ -1307,9 +1318,11 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
                goto out;
        }
 
+       ext_size = sizeof(EXT4_I(inode)->i_data);
        /* move top-level index/leaf into new block */
-       memmove(bh->b_data, EXT4_I(inode)->i_data,
-               sizeof(EXT4_I(inode)->i_data));
+       memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
+       /* zero out unused area in the extent block */
+       memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
 
        /* set size of new block */
        neh = ext_block_hdr(bh);