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authorTheodore Ts'o <tytso@mit.edu>2018-06-15 12:28:16 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-11 16:31:30 +0200
commit0abaed0c74f4dbd3f5a9dcb9fb6b472735874b5e (patch)
parent6af469f553b5c3e5fe10449ad38bbadc11fb1d31 (diff)
ext4: clear i_data in ext4_inode_info when removing inline data
commit 6e8ab72a812396996035a37e5ca4b3b99b5d214b upstream. When converting from an inode from storing the data in-line to a data block, ext4_destroy_inline_data_nolock() was only clearing the on-disk copy of the i_blocks[] array. It was not clearing copy of the i_blocks[] in ext4_inode_info, in i_data[], which is the copy actually used by ext4_map_blocks(). This didn't matter much if we are using extents, since the extents header would be invalid and thus the extents could would re-initialize the extents tree. But if we are using indirect blocks, the previous contents of the i_blocks array will be treated as block numbers, with potentially catastrophic results to the file system integrity and/or user data. This gets worse if the file system is using a 1k block size and s_first_data is zero, but even without this, the file system can get quite badly corrupted. This addresses CVE-2018-10881. https://bugzilla.kernel.org/show_bug.cgi?id=200015 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 44b4fcdc3755..d79115d8d716 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -437,6 +437,7 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle,
memset((void *)ext4_raw_inode(&is.iloc)->i_block,
+ memset(ei->i_data, 0, EXT4_MIN_INLINE_DATA_SIZE);
if (ext4_has_feature_extents(inode->i_sb)) {
if (S_ISDIR(inode->i_mode) ||