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authorAnna Schumaker <Anna.Schumaker@Netapp.com>2023-05-16 11:19:25 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-09-13 09:43:05 +0200
commit7795634751622709cab9ce4cad2bcd93f871fae3 (patch)
tree6e94b1d92e049b0648f4c9c093dad0c465e3dad5
parentd9ece8c0269f4efe391bfa1022266bdb78d8cbad (diff)
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NFSv4.2: Fix a potential double free with READ_PLUS
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@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfs/nfs4proc.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 3f96ccc386c3..b707a23c25e9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5444,10 +5444,18 @@ static bool nfs4_read_plus_not_supported(struct rpc_task *task,
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))