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

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

[gregkh]

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@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 8179a101eb5f4ef0ac9a915fcea9a9d3109efa90 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
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 <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>

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;
@@ -2089,13 +2084,11 @@ int __ceph_setattr(struct inode *inode, 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);
+
 	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;
 }
 
 /*

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

[Luis Henriques]

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@vger.kernel.org>.
> 

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

Cheers,
--
Lu�s

>From beab414f9df0c865e73e651393538cde1fa20a3d Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
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@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>
[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@suse.com>
---
 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;
 }
 

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

[Yan, Zheng]

> On 2 May 2017, at 19:10, Luis Henriques <lhenriques@suse.com> wrote:
> 
> 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@vger.kernel.org>.
>> 
> 
> 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@redhat.com>
> 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@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>
> [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@suse.com>
> ---
> 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;
> }

Thank you for the patch. but it does not work  because ceph_set_acl() calls ceph_setattr() directly. I think we need to introduce __ceph_setattr()  and make ceph_set_acl() call __ceph_setattr()

Regards
Yan, Zheng

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

[Luis Henriques]

On Tue, May 02, 2017 at 07:19:06PM +0800, Yan, Zheng wrote:
[...]
> Thank you for the patch. but it does not work  because ceph_set_acl()
> calls ceph_setattr() directly. I think we need to introduce
> __ceph_setattr()  and make ceph_set_acl() call __ceph_setattr()

Ah, of course!  Maybe something like this:


>From a6751ca41e6096638b75bf9d066338571399e8b4 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
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@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>
[luis: introduce __ceph_setattr() and make ceph_set_acl() call it, as
 suggested by Yan.]
Signed-off-by: Luis Henriques <lhenriques@suse.com>
---
 fs/ceph/acl.c   |  4 ++--
 fs/ceph/inode.c | 27 ++++++++++++++++-----------
 fs/ceph/super.h |  1 +
 3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 4d8caeb94a11..bdb9c94335f1 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -128,7 +128,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	if (new_mode != old_mode) {
 		newattrs.ia_mode = new_mode;
 		newattrs.ia_valid = ATTR_MODE;
-		ret = ceph_setattr(dentry, &newattrs);
+		ret = __ceph_setattr(dentry, &newattrs);
 		if (ret)
 			goto out_dput;
 	}
@@ -138,7 +138,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 		if (new_mode != old_mode) {
 			newattrs.ia_mode = old_mode;
 			newattrs.ia_valid = ATTR_MODE;
-			ceph_setattr(dentry, &newattrs);
+			__ceph_setattr(dentry, &newattrs);
 		}
 		goto out_dput;
 	}
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index d98536c8abfc..9f0d99094cc1 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1773,7 +1773,7 @@ static const struct inode_operations ceph_symlink_iops = {
 /*
  * setattr
  */
-int ceph_setattr(struct dentry *dentry, struct iattr *attr)
+int __ceph_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	struct ceph_inode_info *ci = ceph_inode(inode);
@@ -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 +1988,23 @@ 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);
+
+	if (err >= 0 && (mask & CEPH_SETATTR_SIZE))
+		__ceph_do_pending_vmtruncate(inode);
+
 	return err;
-out_put:
-	ceph_mdsc_put_request(req);
-	ceph_free_cap_flush(prealloc_cf);
+}
+
+int ceph_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	int err;
+
+	err = __ceph_setattr(dentry, attr);
+
+	if (err >= 0 && (attr->ia_valid & ATTR_MODE))
+		err = posix_acl_chmod(d_inode(dentry), attr->ia_mode);
+
 	return err;
 }
 
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 75b7d125ce66..8c8cb8fe3d32 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -788,6 +788,7 @@ static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
 	return __ceph_do_getattr(inode, NULL, mask, force);
 }
 extern int ceph_permission(struct inode *inode, int mask);
+extern int __ceph_setattr(struct dentry *dentry, struct iattr *attr);
 extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
 extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
 			struct kstat *stat);

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

[Yan, Zheng]

> On 2 May 2017, at 21:02, Luis Henriques <lhenriques@suse.com> wrote:
> 
> On Tue, May 02, 2017 at 07:19:06PM +0800, Yan, Zheng wrote:
> [...]
>> Thank you for the patch. but it does not work  because ceph_set_acl()
>> calls ceph_setattr() directly. I think we need to introduce
>> __ceph_setattr()  and make ceph_set_acl() call __ceph_setattr()
> 
> Ah, of course!  Maybe something like this:
> 
> 
> From a6751ca41e6096638b75bf9d066338571399e8b4 Mon Sep 17 00:00:00 2001
> From: "Yan, Zheng" <zyan@redhat.com>
> 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@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>
> [luis: introduce __ceph_setattr() and make ceph_set_acl() call it, as
> suggested by Yan.]
> Signed-off-by: Luis Henriques <lhenriques@suse.com>
> ---
> fs/ceph/acl.c   |  4 ++--
> fs/ceph/inode.c | 27 ++++++++++++++++-----------
> fs/ceph/super.h |  1 +
> 3 files changed, 19 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
> index 4d8caeb94a11..bdb9c94335f1 100644
> --- a/fs/ceph/acl.c
> +++ b/fs/ceph/acl.c
> @@ -128,7 +128,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
> 	if (new_mode != old_mode) {
> 		newattrs.ia_mode = new_mode;
> 		newattrs.ia_valid = ATTR_MODE;
> -		ret = ceph_setattr(dentry, &newattrs);
> +		ret = __ceph_setattr(dentry, &newattrs);
> 		if (ret)
> 			goto out_dput;
> 	}
> @@ -138,7 +138,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
> 		if (new_mode != old_mode) {
> 			newattrs.ia_mode = old_mode;
> 			newattrs.ia_valid = ATTR_MODE;
> -			ceph_setattr(dentry, &newattrs);
> +			__ceph_setattr(dentry, &newattrs);
> 		}
> 		goto out_dput;
> 	}
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index d98536c8abfc..9f0d99094cc1 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -1773,7 +1773,7 @@ static const struct inode_operations ceph_symlink_iops = {
> /*
>  * setattr
>  */
> -int ceph_setattr(struct dentry *dentry, struct iattr *attr)
> +int __ceph_setattr(struct dentry *dentry, struct iattr *attr)
> {
> 	struct inode *inode = d_inode(dentry);
> 	struct ceph_inode_info *ci = ceph_inode(inode);
> @@ -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 +1988,23 @@ 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);
> +
> +	if (err >= 0 && (mask & CEPH_SETATTR_SIZE))
> +		__ceph_do_pending_vmtruncate(inode);
> +
> 	return err;
> -out_put:
> -	ceph_mdsc_put_request(req);
> -	ceph_free_cap_flush(prealloc_cf);
> +}
> +
> +int ceph_setattr(struct dentry *dentry, struct iattr *attr)
> +{
> +	int err;
> +
> +	err = __ceph_setattr(dentry, attr);
> +
> +	if (err >= 0 && (attr->ia_valid & ATTR_MODE))
> +		err = posix_acl_chmod(d_inode(dentry), attr->ia_mode);
> +
> 	return err;
> }
> 
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 75b7d125ce66..8c8cb8fe3d32 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -788,6 +788,7 @@ static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
> 	return __ceph_do_getattr(inode, NULL, mask, force);
> }
> extern int ceph_permission(struct inode *inode, int mask);
> +extern int __ceph_setattr(struct dentry *dentry, struct iattr *attr);
> extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
> extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
> 			struct kstat *stat);


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