> On Mar 27, 2023, at 6:21 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > For ops with "trivial" replies, nfsd4_encode_operation will shortcut > most of the encoding work and skip to just marshalling up the status. > One of the things it skips is calling op_release. This could cause a > memory leak in the layoutget codepath if there is an error at an > inopportune time. > > Have the compound processing engine always call op_release, even when > op_func sets an error in op->status. With this change, we also need > nfsd4_block_get_device_info_scsi to set the gd_device pointer to NULL > on error to avoid a double free. > > Reported-by: Zhi Li <yieli@xxxxxxxxxx> > Link: https://bugzilla.redhat.com/show_bug.cgi?id=2181403 > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> Thanks, Jeff. May I add: Fixes: 34b1744c91cc ("nfsd4: define ->op_release for compound ops") ? > --- > fs/nfsd/blocklayout.c | 1 + > fs/nfsd/nfs4xdr.c | 13 +++++++------ > 2 files changed, 8 insertions(+), 6 deletions(-) > > diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c > index 04697f8dc37d..01d7fd108cf3 100644 > --- a/fs/nfsd/blocklayout.c > +++ b/fs/nfsd/blocklayout.c > @@ -297,6 +297,7 @@ nfsd4_block_get_device_info_scsi(struct super_block *sb, > > out_free_dev: > kfree(dev); > + gdp->gd_device = NULL; > return ret; > } > > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index e12e5a4ad502..6b675fbdabd0 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -5402,7 +5402,7 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) > p = xdr_reserve_space(xdr, 8); > if (!p) { > WARN_ON_ONCE(1); > - return; > + goto release; > } > *p++ = cpu_to_be32(op->opnum); > post_err_offset = xdr->buf->len; > @@ -5418,8 +5418,6 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) > op->status = encoder(resp, op->status, &op->u); > if (op->status) > trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status); > - if (opdesc && opdesc->op_release) > - opdesc->op_release(&op->u); > xdr_commit_encode(xdr); > > /* nfsd4_check_resp_size guarantees enough room for error status */ > @@ -5460,11 +5458,14 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op) > } > status: > *p = op->status; > +release: > + if (opdesc && opdesc->op_release) > + opdesc->op_release(&op->u); > } > > -/* > - * Encode the reply stored in the stateowner reply cache > - * > +/* > + * Encode the reply stored in the stateowner reply cache > + * > * XDR note: do not encode rp->rp_buflen: the buffer contains the > * previously sent already encoded operation. > */ > -- > 2.39.2 > -- Chuck Lever
