diff options
author | Jan Kara <jack@suse.cz> | 2016-09-19 18:39:09 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-08 08:44:10 +0300 |
commit | d8333c045f045385a914013a220cd1ed54c88d48 (patch) | |
tree | 6f3354eeb66b4277f03d695b1c88d1d2f091f6c6 /fs/ext4/acl.c | |
parent | 5a7b3b1ec16b6bfa57752d37292988e64fcdd172 (diff) | |
download | linux-d8333c045f045385a914013a220cd1ed54c88d48.tar.xz |
posix_acl: Clear SGID bit when setting file permissions
commit 073931017b49d9458aa351605b43a7e34598caef upstream.
When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.
References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4/acl.c')
-rw-r--r-- | fs/ext4/acl.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c index d40c8dbbb0d6..87d9bbf6a53f 100644 --- a/fs/ext4/acl.c +++ b/fs/ext4/acl.c @@ -201,15 +201,11 @@ __ext4_set_acl(handle_t *handle, struct inode *inode, int type, case ACL_TYPE_ACCESS: name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; if (acl) { - error = posix_acl_equiv_mode(acl, &inode->i_mode); - if (error < 0) + error = posix_acl_update_mode(inode, &inode->i_mode, &acl); + if (error) return error; - else { - inode->i_ctime = ext4_current_time(inode); - ext4_mark_inode_dirty(handle, inode); - if (error == 0) - acl = NULL; - } + inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); } break; |