3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Based on Ernesto A. Fernández's fix for ext2 (commit fe26569eb919), from which the following description is taken: > When changing a file's acl mask, ext2_set_acl() will first set the group > bits of i_mode to the value of the mask, and only then set the actual > extended attribute representing the new acl. > > If the second part fails (due to lack of space, for example) and the file > had no acl attribute to begin with, the system will from now on assume > that the mask permission bits are actual group permission bits, potentially > granting access to the wrong users. > > Prevent this by only changing the inode mode after the acl has been set. Cc: Ernesto A. Fernández <ernesto.mnd.fernandez@xxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- fs/ext3/acl.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/fs/ext3/acl.c +++ b/fs/ext3/acl.c @@ -227,19 +227,25 @@ ext3_set_acl(struct inode *inode, struct { handle_t *handle; int error, retries = 0; + int update_mode = 0; + umode_t mode = inode->i_mode; retry: handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb)); if (IS_ERR(handle)) return PTR_ERR(handle); if (type == ACL_TYPE_ACCESS && acl) { - error = posix_acl_update_mode(inode, &inode->i_mode, &acl); + error = posix_acl_update_mode(inode, &mode, &acl); if (error) goto journal_stop; + update_mode = 1; + } + error = __ext3_set_acl(handle, inode, type, acl); + if (!error && update_mode) { + inode->i_mode = mode; inode->i_ctime = CURRENT_TIME_SEC; ext3_mark_inode_dirty(handle, inode); } - error = __ext3_set_acl(handle, inode, type, acl); journal_stop: ext3_journal_stop(handle); if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))