6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
commit 43439d858bbae244a510de47f9a55f667ca4ed52 upstream.
kfree()-ing the scratch page isn't enough, we also need to set the pointer
back to NULL to avoid a double-free in the case of a resend.
Fixes: fbd2a05f29a9 (NFSv4.2: Rework scratch handling for READ_PLUS)
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5444,10 +5444,18 @@ static bool nfs4_read_plus_not_supported
return false;
}
-static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+static inline void nfs4_read_plus_scratch_free(struct nfs_pgio_header *hdr)
{
- if (hdr->res.scratch)
+ if (hdr->res.scratch) {
kfree(hdr->res.scratch);
+ hdr->res.scratch = NULL;
+ }
+}
+
+static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+ nfs4_read_plus_scratch_free(hdr);
+
if (!nfs4_sequence_done(task, &hdr->res.seq_res))
return -EAGAIN;
if (nfs4_read_stateid_changed(task, &hdr->args))
