nfsd: release OPEN-decoded posix ACLs via op_release

nfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates refcounted struct posix_acl objects via posix_acl_alloc() and stores them in open->op_pacl and open->op_dpacl. These pointers must be released once the OPEN compound finishes.

When nfsd4_decode_open_claim4() returns a non-seqid-mutating error, the dispatcher short-circuits before op_func runs:

    nfsd4_proc_compound()
      opdesc->op_func == nfsd4_open_omfg
        if (!seqid_mutating_err(ntohl(op->status)))
            return op->status;   /* nfsd4_open() never runs */
      opdesc->op_release(&op->u)  /* must still release op_pacl/op_dpacl */

Before this change OP_OPEN had no .op_release in nfsd4_ops[], and the release pair lived inside nfsd4_open() at its out_err: label. On the short-circuit path nfsd4_open() is never invoked, so both posix_acl refs leak on every malformed OPEN compound that carries valid POSIX ACL createhow4 attributes.

Add nfsd4_open_release() and wire it as .op_release for OP_OPEN. posix_acl_release() is NULL-safe, so the single release site covers both the normal path and the nfsd4_open_omfg short-circuit. Remove the matching posix_acl_release() pair from nfsd4_open()'s out_err:
label to avoid double-releasing.

The compound loop has two encoding branches: nfsd4_encode_operation() for normal ops, and nfsd4_encode_replay() for v4.0 replayed ops. op_release was only called from nfsd4_encode_operation(), so resources attached to op->u leak on the replay path. Add an op_release call to the replay branch as well to ensure cleanup on every path.

Fixes 5fc51dfc2eb1 ("NFSD: Add support for XDR decoding POSIX draft ACLs")

Signed-off-by Chris Mason <[email protected]>

Reviewed-by Chuck Lever <[email protected]>

Signed-off-by Jeff Layton <[email protected]>

---
Changes in v2:
- Ensure that op_release is called in the v4.0 replay case as well
- Link to v1: https://lore.kernel.org/r/[email protected]

---
 fs/nfsd/nfs4proc.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

fs/nfsd/nfs4proc.c +7 -2

index 017474cd63b5..51998d7885ae 100644
@@ -681,8 +681,6 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	nfsd4_cleanup_open_state(cstate, open);
 	nfsd4_bump_seqid(cstate, status);
 out_err:
-	posix_acl_release(open->op_dpacl);
-	posix_acl_release(open->op_pacl);
 	return status;
 }
 

@@ -704,6 +702,13 @@ static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_stat
 	return nfsd4_open(rqstp, cstate, &op->u);
 }
 
+static void
+nfsd4_open_release(union nfsd4_op_u *u)
+{
+	posix_acl_release(u->open.op_dpacl);
+	posix_acl_release(u->open.op_pacl);
+}
+
 /*
  * filehandle-manipulating ops.
  */

fs/nfsd/nfs4proc.c +1 -1

@@ -3718,6 +3725,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_OPEN] = {
 		.op_func = nfsd4_open,
+		.op_release = nfsd4_open_release,
 		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
 		.op_name = "OP_OPEN",
 		.op_rsize_bop = nfsd4_open_rsize,
 
---

base-commit: 6c0004650ba248a12937ada16f9ba961b35ce2b5
change-id: 20260531-nfsd-testing-9122bf51ce95

Best regards,

Signature · 1 line

Jeff Layton <[email protected]>

Quoted 72 lines · Jeff Layton

nfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates refcounted struct posix_acl objects via posix_acl_alloc() and stores them in open->op_pacl and open->op_dpacl. These pointers must be released once the OPEN compound finishes.

When nfsd4_decode_open_claim4() returns a non-seqid-mutating error, the dispatcher short-circuits before op_func runs:

    nfsd4_proc_compound()
      opdesc->op_func == nfsd4_open_omfg
        if (!seqid_mutating_err(ntohl(op->status)))
            return op->status;   /* nfsd4_open() never runs */
      opdesc->op_release(&op->u)  /* must still release op_pacl/op_dpacl */

Before this change OP_OPEN had no .op_release in nfsd4_ops[], and the release pair lived inside nfsd4_open() at its out_err: label. On the short-circuit path nfsd4_open() is never invoked, so both posix_acl refs leak on every malformed OPEN compound that carries valid POSIX ACL createhow4 attributes.

Add nfsd4_open_release() and wire it as .op_release for OP_OPEN. posix_acl_release() is NULL-safe, so the single release site covers both the normal path and the nfsd4_open_omfg short-circuit. Remove the matching posix_acl_release() pair from nfsd4_open()'s out_err:
label to avoid double-releasing.

The compound loop has two encoding branches: nfsd4_encode_operation() for normal ops, and nfsd4_encode_replay() for v4.0 replayed ops. op_release was only called from nfsd4_encode_operation(), so resources attached to op->u leak on the replay path. Add an op_release call to the replay branch as well to ensure cleanup on every path.

Fixes 5fc51dfc2eb1 ("NFSD: Add support for XDR decoding POSIX draft ACLs")

Signed-off-by Chris Mason <[email protected]>

Reviewed-by Chuck Lever <[email protected]>

Signed-off-by Jeff Layton <[email protected]>

---
Changes in v2:
- Ensure that op_release is called in the v4.0 replay case as well
- Link to v1: https://lore.kernel.org/r/[email protected]

---
 fs/nfsd/nfs4proc.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

fs/nfsd/nfs4proc.c +7 -2

index 017474cd63b5..51998d7885ae 100644
@@ -681,8 +681,6 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	nfsd4_cleanup_open_state(cstate, open);
 	nfsd4_bump_seqid(cstate, status);
 out_err:
-	posix_acl_release(open->op_dpacl);
-	posix_acl_release(open->op_pacl);
 	return status;
 }
 

@@ -704,6 +702,13 @@ static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_stat
 	return nfsd4_open(rqstp, cstate, &op->u);
 }
 
+static void
+nfsd4_open_release(union nfsd4_op_u *u)
+{
+	posix_acl_release(u->open.op_dpacl);
+	posix_acl_release(u->open.op_pacl);
+}
+
 /*
  * filehandle-manipulating ops.
  */

fs/nfsd/nfs4proc.c nfsd4_proc_compound(struct svc_rqst *rqstp) · line 3226

Quoted 8 lines

fs/nfsd/nfs4proc.c +2 -0

@@ -3214,6 +3219,8 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
 			op->replay = &cstate->replay_owner->so_replay;
 			nfsd4_encode_replay(resp->xdr, op);
 			status = op->status = op->replay->rp_status;
+			if (op->opdesc->op_release)
+				op->opdesc->op_release(&op->u);
 		} else {
 			nfsd4_encode_operation(resp, op);
 			status = op->status;

I think this patch is good, but I think it would be even better if the ->op_release() call were moved out of nfsd4_encode_operation() and places after this if-else. Then there would be only one call-site in a fairly obviously-correct place.
But:

Reviewed-by NeilBrown <[email protected]>

for if you just want to stick with this version.

Thanks,
NeilBrown

Quoted 19 lines

fs/nfsd/nfs4proc.c +1 -1

@@ -3718,6 +3725,7 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 	},
 	[OP_OPEN] = {
 		.op_func = nfsd4_open,
+		.op_release = nfsd4_open_release,
 		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
 		.op_name = "OP_OPEN",
 		.op_rsize_bop = nfsd4_open_rsize,
 
---

base-commit: 6c0004650ba248a12937ada16f9ba961b35ce2b5
change-id: 20260531-nfsd-testing-9122bf51ce95

Best regards,

Signature · 1 line

Jeff Layton <[email protected]>

Quoted 11 lines · NeilBrown

I think this patch is good, but I think it would be even better if the ->op_release() call were moved out of nfsd4_encode_operation() and places after this if-else. Then there would be only one call-site in a fairly obviously-correct place.
But:

Reviewed-by NeilBrown <[email protected]>

for if you just want to stick with this version.

Thanks,
NeilBrown

I like that idea.

I'll be testing a pile of other patches today anyway, so I'll make this change and test it alongside the rest.

Chuck, you can either take this one and I'll do a cleanup patch along the lines of what Neil suggests, or I can send a v3.