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| author | Jeff Layton <jlayton@kernel.org> | 2026-05-21 07:50:21 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-04 13:45:08 +0200 |
| commit | 8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e (patch) | |
| tree | 0d97b91d919dcdd79024c9010761c81cb0eca62e | |
| parent | ff3ecd17db74a6a97e6b19d920420382ddf6bca1 (diff) | |
| download | linux-8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e.tar.gz linux-8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e.zip | |
nfsd: fix dead ACL conflict guard in nfsd4_create
commit a60f25a800846ab8e5a13f8a9d05111f2aee55a7 upstream.
nfsd4_create() steals create->cr_dpacl/cr_pacl into the local
nfsd_attrs via the designated initializer, then immediately sets the
source pointers to NULL. The subsequent conflict guard tests the
already-nilled source fields, making it permanently dead code:
if (create->cr_acl) {
if (create->cr_dpacl || create->cr_pacl) /* always false */
When a client encodes both FATTR4_WORD0_ACL and
FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr
bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without
releasing the originals, leaking two posix_acl slab objects per
request. Repeated requests cause unbounded slab exhaustion.
Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of
the nilled create->cr_dpacl/cr_pacl, matching the correct pattern
already used in nfsd4_setattr().
Reported-by: Chris Mason <clm@meta.com>
Assisted-by: kres:claude-opus-4-6
Fixes: d2ca50606f5f ("NFSD: Add support for POSIX draft ACLs for file creation")
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nfsd/nfs4proc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 3428eaf971f5..8561540ab2db 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -840,7 +840,7 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out_aftermask; if (create->cr_acl) { - if (create->cr_dpacl || create->cr_pacl) { + if (attrs.na_dpacl || attrs.na_pacl) { status = nfserr_inval; goto out_aftermask; } |