From a6ccb36b948efed0eeee4fcf99fe4b5fb81ae1d5 Mon Sep 17 00:00:00 2001 From: Richard Yao Date: Wed, 12 Oct 2022 14:25:18 -0400 Subject: [PATCH] Add defensive assertions Coverity complains about possible bugs involving referencing NULL return values and division by zero. The division by zero bugs require that a block pointer be corrupt, either from in-memory corruption, or on-disk corruption. The NULL return value complaints are only bugs if assumptions that we make about the state of data structures are wrong. Some seem impossible to be wrong and thus are false positives, while others are hard to analyze. Rather than dismiss these as false positives by assuming we know better, we add defensive assertions to let us know when our assumptions are wrong. Reviewed-by: Brian Behlendorf Signed-off-by: Richard Yao Closes #13972 --- cmd/zdb/zdb_il.c | 1 + module/os/freebsd/zfs/zfs_acl.c | 1 + module/os/linux/zfs/zfs_acl.c | 1 + module/zfs/arc.c | 1 + module/zfs/dbuf.c | 2 ++ module/zfs/dmu_traverse.c | 1 + module/zfs/dsl_deadlist.c | 1 + module/zfs/dsl_scan.c | 1 + module/zfs/mmp.c | 4 +++- module/zfs/range_tree.c | 1 + module/zfs/spa_log_spacemap.c | 1 + module/zfs/vdev_indirect.c | 1 + module/zfs/vdev_queue.c | 1 + module/zfs/zil.c | 1 + 14 files changed, 17 insertions(+), 1 deletion(-) diff --git a/cmd/zdb/zdb_il.c b/cmd/zdb/zdb_il.c index 4de7619e4..02cc10fb7 100644 --- a/cmd/zdb/zdb_il.c +++ b/cmd/zdb/zdb_il.c @@ -182,6 +182,7 @@ zil_prt_rec_write(zilog_t *zilog, int txtype, const void *arg) return; } + ASSERT3U(BP_GET_LSIZE(bp), !=, 0); SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); diff --git a/module/os/freebsd/zfs/zfs_acl.c b/module/os/freebsd/zfs/zfs_acl.c index 963102f3b..a85d4c241 100644 --- a/module/os/freebsd/zfs/zfs_acl.c +++ b/module/os/freebsd/zfs/zfs_acl.c @@ -1133,6 +1133,7 @@ zfs_acl_data_locator(void **dataptr, uint32_t *length, uint32_t buflen, cb->cb_acl_node = list_next(&cb->cb_aclp->z_acl, cb->cb_acl_node); } + ASSERT3P(cb->cb_acl_node, !=, NULL); *dataptr = cb->cb_acl_node->z_acldata; *length = cb->cb_acl_node->z_size; } diff --git a/module/os/linux/zfs/zfs_acl.c b/module/os/linux/zfs/zfs_acl.c index 5935403b4..d5cd5de89 100644 --- a/module/os/linux/zfs/zfs_acl.c +++ b/module/os/linux/zfs/zfs_acl.c @@ -1163,6 +1163,7 @@ zfs_acl_data_locator(void **dataptr, uint32_t *length, uint32_t buflen, cb->cb_acl_node = list_next(&cb->cb_aclp->z_acl, cb->cb_acl_node); } + ASSERT3P(cb->cb_acl_node, !=, NULL); *dataptr = cb->cb_acl_node->z_acldata; *length = cb->cb_acl_node->z_size; } diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 33865f715..9254d8b84 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -8539,6 +8539,7 @@ l2arc_dev_get_next(void) else if (next == first) break; + ASSERT3P(next, !=, NULL); } while (vdev_is_dead(next->l2ad_vdev) || next->l2ad_rebuild || next->l2ad_trim_all); diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index db1123d37..85de95baf 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -2687,6 +2687,7 @@ dbuf_override_impl(dmu_buf_impl_t *db, const blkptr_t *bp, dmu_tx_t *tx) dbuf_dirty_record_t *dr; dr = list_head(&db->db_dirty_records); + ASSERT3P(dr, !=, NULL); ASSERT3U(dr->dr_txg, ==, tx->tx_txg); dl = &dr->dt.dl; dl->dr_overridden_by = *bp; @@ -2748,6 +2749,7 @@ dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data, dmu_buf_will_not_fill(dbuf, tx); dr = list_head(&db->db_dirty_records); + ASSERT3P(dr, !=, NULL); ASSERT3U(dr->dr_txg, ==, tx->tx_txg); dl = &dr->dt.dl; encode_embedded_bp_compressed(&dl->dr_overridden_by, diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c index 2ed75640f..d712133cd 100644 --- a/module/zfs/dmu_traverse.c +++ b/module/zfs/dmu_traverse.c @@ -111,6 +111,7 @@ traverse_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg, if (claim_txg == 0 || bp->blk_birth < claim_txg) return (0); + ASSERT3U(BP_GET_LSIZE(bp), !=, 0); SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid, ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); diff --git a/module/zfs/dsl_deadlist.c b/module/zfs/dsl_deadlist.c index 1ecae0fe3..031be59e3 100644 --- a/module/zfs/dsl_deadlist.c +++ b/module/zfs/dsl_deadlist.c @@ -542,6 +542,7 @@ dsl_deadlist_remove_key(dsl_deadlist_t *dl, uint64_t mintxg, dmu_tx_t *tx) dle = avl_find(&dl->dl_tree, &dle_tofind, NULL); ASSERT3P(dle, !=, NULL); dle_prev = AVL_PREV(&dl->dl_tree, dle); + ASSERT3P(dle_prev, !=, NULL); dle_enqueue_subobj(dl, dle_prev, dle->dle_bpobj.bpo_object, tx); diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c index f0cd1feaf..09e271395 100644 --- a/module/zfs/dsl_scan.c +++ b/module/zfs/dsl_scan.c @@ -1470,6 +1470,7 @@ dsl_scan_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg, if (claim_txg == 0 || bp->blk_birth < claim_txg) return (0); + ASSERT3U(BP_GET_LSIZE(bp), !=, 0); SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], lr->lr_foid, ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); diff --git a/module/zfs/mmp.c b/module/zfs/mmp.c index 92fd6c422..b6d71aa8a 100644 --- a/module/zfs/mmp.c +++ b/module/zfs/mmp.c @@ -303,8 +303,10 @@ mmp_next_leaf(spa_t *spa) do { leaf = list_next(&spa->spa_leaf_list, leaf); - if (leaf == NULL) + if (leaf == NULL) { leaf = list_head(&spa->spa_leaf_list); + ASSERT3P(leaf, !=, NULL); + } /* * We skip unwritable, offline, detached, and dRAID spare diff --git a/module/zfs/range_tree.c b/module/zfs/range_tree.c index a2923d166..894c30fca 100644 --- a/module/zfs/range_tree.c +++ b/module/zfs/range_tree.c @@ -369,6 +369,7 @@ range_tree_add_impl(void *arg, uint64_t start, uint64_t size, uint64_t fill) * invalid as soon as we do any mutating btree operations. */ rs_after = zfs_btree_find(&rt->rt_root, &tmp, &where_after); + ASSERT3P(rs_after, !=, NULL); rs_set_start_raw(rs_after, rt, before_start); rs_set_fill(rs_after, rt, after_fill + before_fill + fill); rs = rs_after; diff --git a/module/zfs/spa_log_spacemap.c b/module/zfs/spa_log_spacemap.c index 4ecce8214..5ce60bf21 100644 --- a/module/zfs/spa_log_spacemap.c +++ b/module/zfs/spa_log_spacemap.c @@ -507,6 +507,7 @@ void spa_log_summary_decrement_blkcount(spa_t *spa, uint64_t blocks_gone) { log_summary_entry_t *e = list_head(&spa->spa_log_summary); + ASSERT3P(e, !=, NULL); if (e->lse_txgcount > 0) e->lse_txgcount--; for (; e != NULL; e = list_head(&spa->spa_log_summary)) { diff --git a/module/zfs/vdev_indirect.c b/module/zfs/vdev_indirect.c index 0ca0c245e..b0bd71c58 100644 --- a/module/zfs/vdev_indirect.c +++ b/module/zfs/vdev_indirect.c @@ -1319,6 +1319,7 @@ vdev_indirect_io_start(zio_t *zio) vdev_indirect_gather_splits, zio); indirect_split_t *first = list_head(&iv->iv_splits); + ASSERT3P(first, !=, NULL); if (first->is_size == zio->io_size) { /* * This is not a split block; we are pointing to the entire diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c index 1acb89cea..f4e8d1427 100644 --- a/module/zfs/vdev_queue.c +++ b/module/zfs/vdev_queue.c @@ -756,6 +756,7 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio) do { dio = nio; nio = AVL_NEXT(t, dio); + ASSERT3P(dio, !=, NULL); zio_add_child(dio, aio); vdev_queue_io_remove(vq, dio); diff --git a/module/zfs/zil.c b/module/zfs/zil.c index dc5b8018e..075bac832 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -339,6 +339,7 @@ zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) if (wbuf == NULL) zio_flags |= ZIO_FLAG_RAW; + ASSERT3U(BP_GET_LSIZE(bp), !=, 0); SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));