Re: FAILED: patch "[PATCH] ceph: fix recursion between ceph_set_acl() and" failed to apply to 4.4-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sun, Apr 30, 2017 at 04:04:39PM +0200, Greg Kroah-Hartman wrote:
> 
> The patch below does not apply to the 4.4-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
> 

Here's a backport I've tested with 4.4.

Cheers,
--
Luís

>From beab414f9df0c865e73e651393538cde1fa20a3d Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@xxxxxxxxxx>
Date: Wed, 19 Apr 2017 10:01:48 +0800
Subject: [PATCH] ceph: fix recursion between ceph_set_acl() and
 __ceph_setattr()

commit 8179a101eb5f4ef0ac9a915fcea9a9d3109efa90 upstream.

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@xxxxxxxxxxxxxxx # needs backporting for < 4.9
Link: http://tracker.ceph.com/issues/19688
Reported-by: Jerry Lee <leisurelysw24@xxxxxxxxx>
Signed-off-by: "Yan, Zheng" <zyan@xxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Tested-by: Luis Henriques <lhenriques@xxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
[luis: __ceph_setattr doesn't exist in 4.4, implement all the changes
 directly in ceph_setattr.  The wrapper function was introduced only in
 commit a26feccaba29 ("ceph: Get rid of d_find_alias in ceph_set_acl").]
Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx>
---
 fs/ceph/inode.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index d98536c8abfc..e3d19c3d246d 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1975,11 +1975,6 @@ int ceph_setattr(struct dentry *dentry, 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;
@@ -1993,13 +1988,14 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
 	     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);
+
+	if (err >= 0 && (attr->ia_valid & ATTR_MODE))
+		err = posix_acl_chmod(inode, attr->ia_mode);
+
 	return err;
 }
 



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]