From f1317a4a2b9b289cff6c993a9132d83c8136599f Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Fri, 27 Mar 2020 07:50:40 +0300 Subject: [PATCH] nfsd: memory corruption in nfsd4_lock() commit e1e8399eee72e9d5246d4d1bcacd793debe34dd3 upstream. New struct nfsd4_blocked_lock allocated in find_or_allocate_block() does not initialized nbl_list and nbl_lru. If conflock allocation fails rollback can call list_del_init() access uninitialized fields and corrupt memory. v2: just initialize nbl_list and nbl_lru right after nbl allocation. Fixes: 76d348fadff5 ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock") Signed-off-by: Vasily Averin Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4state.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 1c82d7dd54df..8650a97e2ba9 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -266,6 +266,8 @@ find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh, if (!nbl) { nbl= kmalloc(sizeof(*nbl), GFP_KERNEL); if (nbl) { + INIT_LIST_HEAD(&nbl->nbl_list); + INIT_LIST_HEAD(&nbl->nbl_lru); fh_copy_shallow(&nbl->nbl_fh, fh); locks_init_lock(&nbl->nbl_lock); nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client,