From e1e8399eee72e9d5246d4d1bcacd793debe34dd3 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Fri, 27 Mar 2020 07:50:40 +0300 Subject: nfsd: memory corruption in nfsd4_lock() 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 --- fs/nfsd/nfs4state.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/nfsd') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e32ecedece0f..c107caa56525 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -267,6 +267,8 @@ 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, -- cgit v1.2.3