From: Vasily Averin Date: Fri, 27 Mar 2020 04:50:40 +0000 (+0300) Subject: nfsd: memory corruption in nfsd4_lock() X-Git-Tag: v4.9.221~18 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0ebb05631ce077b1f6f6eb69cb72a6e797863ad6;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 4509c76716e36..5c9231d5e14a0 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -246,6 +246,8 @@ 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,