ext4: fix xattr shifting when expanding inodes part 2 (418c12d0) · Commits · 戴 / test

When multiple xattrs need to be moved out of inode, we did not properly recompute total size of xattr headers in the inode and the new header position. Thus when moving the second and further xattr we asked ext4_xattr_shift_entries() to move too much and from the wrong place, resulting in possible xattr value corruption or general memory corruption. CC: stable@vger.kernel.org # 4.4.x Signed-off-by:

Jan Kara <jack@suse.cz> Signed-off-by:

Theodore Ts'o <tytso@mit.edu>

fs/ext4/xattr.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1516,6 +1516,7 @@ retry:
		error = ext4_xattr_ibody_set(handle, inode, &i, is);
		if (error)
		goto cleanup;
		total_ino -= entry_size;

		entry = IFIRST(header);
		if (entry_size + EXT4_XATTR_SIZE(size) >= isize_diff)
		@@ -1526,11 +1527,11 @@ retry:
		ext4_xattr_shift_entries(entry, -shift_bytes,
		(void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
		EXT4_I(inode)->i_extra_isize + shift_bytes,
		(void *)header, total_ino - entry_size,
		inode->i_sb->s_blocksize);
		(void *)header, total_ino, inode->i_sb->s_blocksize);

		isize_diff -= shift_bytes;
		EXT4_I(inode)->i_extra_isize += shift_bytes;
		header = IHDR(inode, raw_inode);

		i.name = b_entry_name;
		i.value = buffer;

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