[PATCH] nfsd: call op_release, even when op_func returns an error
From: Jeff Layton <jlayton@kernel.org>
Date: 2023-03-27 10:21:46
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd block and scsi layout driver, kernel nfsd, sunrpc, and lockd servers, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, Linus Torvalds
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 <redacted> Link: https://bugzilla.redhat.com/show_bug.cgi?id=2181403 Signed-off-by: Jeff Layton <jlayton@kernel.org> --- 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