From: Theodore Ts'o Date: Tue, 7 Jan 2014 17:58:19 +0000 (-0500) Subject: ext4: avoid clearing beyond i_blocks when truncating an inline data file X-Git-Tag: firefly_0821_release~3679^2~2967 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=209bd086e423d98ddf2fd52a6f1afda15b5758b1;p=firefly-linux-kernel-4.4.55.git ext4: avoid clearing beyond i_blocks when truncating an inline data file commit 09c455aaa8f47a94d5bafaa23d58365768210507 upstream. A missing cast means that when we are truncating a file which is less than 60 bytes, we don't clear the correct area of memory, and in fact we can end up truncating the next inode in the inode table, or worse yet, some other kernel data structure. Addresses-Coverity-Id: #751987 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 33331b4c2178..e350be6c7ac6 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -1957,9 +1957,11 @@ void ext4_inline_data_truncate(struct inode *inode, int *has_inline) } /* Clear the content within i_blocks. */ - if (i_size < EXT4_MIN_INLINE_DATA_SIZE) - memset(ext4_raw_inode(&is.iloc)->i_block + i_size, 0, - EXT4_MIN_INLINE_DATA_SIZE - i_size); + if (i_size < EXT4_MIN_INLINE_DATA_SIZE) { + void *p = (void *) ext4_raw_inode(&is.iloc)->i_block; + memset(p + i_size, 0, + EXT4_MIN_INLINE_DATA_SIZE - i_size); + } EXT4_I(inode)->i_inline_size = i_size < EXT4_MIN_INLINE_DATA_SIZE ?