From 8179a101eb5f4ef0ac9a915fcea9a9d3109efa90 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Wed, 19 Apr 2017 10:01:48 +0800 Subject: [PATCH] ceph: fix recursion between ceph_set_acl() and __ceph_setattr() ceph_set_acl() calls __ceph_setattr() if the setacl operation needs to modify inode's i_mode. __ceph_setattr() updates inode's i_mode, then calls posix_acl_chmod(). The problem is that __ceph_setattr() calls posix_acl_chmod() before sending the setattr request. The get_acl() call in posix_acl_chmod() can trigger a getxattr request. The reply of the getxattr request can restore inode's i_mode to its old value. The set_acl() call in posix_acl_chmod() sees old value of inode's i_mode, so it calls __ceph_setattr() again. Cc: stable@vger.kernel.org # needs backporting for < 4.9 Link: http://tracker.ceph.com/issues/19688 Reported-by: Jerry Lee Signed-off-by: "Yan, Zheng" Reviewed-by: Jeff Layton Tested-by: Luis Henriques Signed-off-by: Ilya Dryomov --- fs/ceph/inode.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index d449e1c03cbd..d3119fe3ab45 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -2071,11 +2071,6 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr) if (inode_dirty_flags) __mark_inode_dirty(inode, inode_dirty_flags); - if (ia_valid & ATTR_MODE) { - err = posix_acl_chmod(inode, attr->ia_mode); - if (err) - goto out_put; - } if (mask) { req->r_inode = inode; @@ -2088,14 +2083,12 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr) dout("setattr %p result=%d (%s locally, %d remote)\n", inode, err, ceph_cap_string(dirtied), mask); - ceph_mdsc_put_request(req); - if (mask & CEPH_SETATTR_SIZE) - __ceph_do_pending_vmtruncate(inode); - ceph_free_cap_flush(prealloc_cf); - return err; -out_put: ceph_mdsc_put_request(req); ceph_free_cap_flush(prealloc_cf); + + if (err >= 0 && (mask & CEPH_SETATTR_SIZE)) + __ceph_do_pending_vmtruncate(inode); + return err; } @@ -2114,7 +2107,12 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) if (err != 0) return err; - return __ceph_setattr(inode, attr); + err = __ceph_setattr(inode, attr); + + if (err >= 0 && (attr->ia_valid & ATTR_MODE)) + err = posix_acl_chmod(inode, attr->ia_mode); + + return err; } /* -- 2.20.1