FAILED: patch "[PATCH] nfsd: gate nfs2 setacl by argp->mask" failed to apply to 6.1-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.1-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>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x a3a7e20ed66d3f04d37883c398da8a113b430769
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090349-thorn-wispy-da17@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From a3a7e20ed66d3f04d37883c398da8a113b430769 Mon Sep 17 00:00:00 2001
From: Chuck Lever <cel@kernel.org>
Date: Sat, 30 May 2026 16:58:16 -0400
Subject: [PATCH] nfsd: gate nfs2 setacl by argp->mask

The NFSACL v2 SETACL path shares the decoder convention used by its
v3 sibling: nfsaclsvc_decode_setaclargs() fills in argp->acl_access
only when NFS_ACL is set in the request mask and argp->acl_default
only when NFS_DFACL is set, leaving the other pointer NULL because
the argument buffer is zeroed up to pc_argzero before decode.

nfsacld_proc_setacl() then hands both pointers to set_posix_acl()
unconditionally. set_posix_acl(idmap, dentry, type, NULL) is the VFS
"remove this ACL type" operation, so an omitted arm is
indistinguishable from an explicit request to delete that ACL. A
SETACL carrying only NFS_ACL silently strips the directory's default
ACL; mask=0 strips both.

This is the same defect just fixed in nfsd3_proc_setacl(); apply the
same remedy. Gate each set_posix_acl() call on its mask bit and
initialize error to 0 so that a request with neither bit set leaves
the on-disk ACLs untouched and returns success. The out_drop_lock
path and the unconditional posix_acl_release() in
nfsaclsvc_release_setacl() already tolerate the skipped arms.

Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.")
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
index 76305b86c1a9..827f90194c43 100644
--- a/fs/nfsd/nfs2acl.c
+++ b/fs/nfsd/nfs2acl.c
@@ -115,14 +115,19 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
 
 	inode_lock(inode);
 
-	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_ACCESS,
-			      argp->acl_access);
-	if (error)
-		goto out_drop_lock;
-	error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry, ACL_TYPE_DEFAULT,
-			      argp->acl_default);
-	if (error)
-		goto out_drop_lock;
+	error = 0;
+	if (argp->mask & NFS_ACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_ACCESS, argp->acl_access);
+		if (error)
+			goto out_drop_lock;
+	}
+	if (argp->mask & NFS_DFACL) {
+		error = set_posix_acl(&nop_mnt_idmap, fh->fh_dentry,
+				      ACL_TYPE_DEFAULT, argp->acl_default);
+		if (error)
+			goto out_drop_lock;
+	}
 
 	inode_unlock(inode);