ceph: fix recursion between ceph_set_acl() and __ceph_setattr() (8179a101) · Commits · 戴 / test

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 <leisurelysw24@gmail.com> Signed-off-by:

"Yan, Zheng" <zyan@redhat.com> Reviewed-by:

Jeff Layton <jlayton@redhat.com> Tested-by:

Luis Henriques <lhenriques@suse.com> Signed-off-by:

Ilya Dryomov <idryomov@gmail.com>

fs/ceph/inode.c

+10 −12

Original line number	Diff line number	Diff line
		@@ -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;
		}

		/*

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