[PATCH 1/2] NFSD: Fix use-after-free warning when doing inter-server copy

Dai Ngo
2020-10-29T19:07:27Z

The source file nfsd_file is not constructed the same as other
nfsd_file's via nfsd_file_alloc. nfsd_file_put should not be
called to free the object; nfsd_file_put is not the inverse of
kzalloc, instead kfree is called by nfsd4_do_async_copy when done.

Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
fs/nfsd/nfs4proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index ad2fa1a8e7ad..9c43cad7e408 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1299,7 +1299,7 @@ nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct nfsd_file *src,
struct nfsd_file *dst)
{
nfs42_ssc_close(src->nf_file);
- nfsd_file_put(src);
+ /* 'src' is freed by nfsd4_do_async_copy */
nfsd_file_put(dst);
mntput(ss_mnt);
}
--
2.20.1.1226.g1595ea5.dirty