From 309e8cda596f6552a32dd14b969ce9b17f837f2f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?= Date: Thu, 31 Aug 2017 07:53:15 -0500 Subject: [PATCH] gfs2: preserve i_mode if __gfs2_set_acl() fails MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When changing a file's acl mask, __gfs2_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. Signed-off-by: Ernesto A. Fernández Signed-off-by: Bob Peterson --- fs/gfs2/acl.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c index a6d962323790..9d5eecb123de 100644 --- a/fs/gfs2/acl.c +++ b/fs/gfs2/acl.c @@ -116,6 +116,7 @@ int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) struct gfs2_holder gh; bool need_unlock = false; int ret; + umode_t mode; if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode))) return -E2BIG; @@ -130,17 +131,19 @@ int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type) return ret; need_unlock = true; } - if (type == ACL_TYPE_ACCESS && acl) { - umode_t mode = inode->i_mode; - ret = posix_acl_update_mode(inode, &inode->i_mode, &acl); + mode = inode->i_mode; + if (type == ACL_TYPE_ACCESS && acl) { + ret = posix_acl_update_mode(inode, &mode, &acl); if (ret) goto unlock; - if (mode != inode->i_mode) - mark_inode_dirty(inode); } ret = __gfs2_set_acl(inode, acl, type); + if (!ret && mode != inode->i_mode) { + inode->i_mode = mode; + mark_inode_dirty(inode); + } unlock: if (need_unlock) gfs2_glock_dq_uninit(&gh); -- 2.20.1