ZIL: Assert record sizes in different places

This should make sure we have log written without overflows.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by:	Alexander Motin <[email protected]>
Sponsored by:	iXsystems, Inc.
Closes #15517 

6 files changed, 115 insertions, 37 deletions

diff --git a/module/os/freebsd/zfs/zio_crypt.c b/module/os/freebsd/zfs/zio_crypt.c
index 024a931d7..b08916b31 100644
--- a/module/os/freebsd/zfs/zio_crypt.c
+++ b/module/os/freebsd/zfs/zio_crypt.c
@@ -1251,7 +1251,7 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
 	iovec_t *dst_iovecs;
 	zil_chain_t *zilc;
 	lr_t *lr;
-	uint64_t txtype, lr_len;
+	uint64_t txtype, lr_len, nused;
 	uint_t crypt_len, nr_iovecs, vec;
 	uint_t aad_len = 0, total_len = 0;
 
@@ -1268,7 +1268,10 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
 	zilc = (zil_chain_t *)src;
 	slrp = src + sizeof (zil_chain_t);
 	aadp = aadbuf;
-	blkend = src + ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
+	nused = ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
+	ASSERT3U(nused, >=, sizeof (zil_chain_t));
+	ASSERT3U(nused, <=, datalen);
+	blkend = src + nused;
 
 	/*
 	 * Calculate the number of encrypted iovecs we will need.
@@ -1287,6 +1290,8 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
 			txtype = lr->lrc_txtype;
 			lr_len = lr->lrc_reclen;
 		}
+		ASSERT3U(lr_len, >=, sizeof (lr_t));
+		ASSERT3U(lr_len, <=, blkend - slrp);
 
 		nr_iovecs++;
 		if (txtype == TX_WRITE && lr_len != sizeof (lr_write_t))
diff --git a/module/os/linux/zfs/zio_crypt.c b/module/os/linux/zfs/zio_crypt.c
index 775ab8efb..2114be281 100644
--- a/module/os/linux/zfs/zio_crypt.c
+++ b/module/os/linux/zfs/zio_crypt.c
@@ -1405,7 +1405,7 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
     boolean_t *no_crypt)
 {
 	int ret;
-	uint64_t txtype, lr_len;
+	uint64_t txtype, lr_len, nused;
 	uint_t nr_src, nr_dst, crypt_len;
 	uint_t aad_len = 0, nr_iovecs = 0, total_len = 0;
 	iovec_t *src_iovecs = NULL, *dst_iovecs = NULL;
@@ -1432,7 +1432,10 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
 	zilc = (zil_chain_t *)src;
 	slrp = src + sizeof (zil_chain_t);
 	aadp = aadbuf;
-	blkend = src + ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
+	nused = ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
+	ASSERT3U(nused, >=, sizeof (zil_chain_t));
+	ASSERT3U(nused, <=, datalen);
+	blkend = src + nused;
 
 	/* calculate the number of encrypted iovecs we will need */
 	for (; slrp < blkend; slrp += lr_len) {
@@ -1445,6 +1448,8 @@ zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
 			txtype = BSWAP_64(lr->lrc_txtype);
 			lr_len = BSWAP_64(lr->lrc_reclen);
 		}
+		ASSERT3U(lr_len, >=, sizeof (lr_t));
+		ASSERT3U(lr_len, <=, blkend - slrp);
 
 		nr_iovecs++;
 		if (txtype == TX_WRITE && lr_len != sizeof (lr_write_t))
diff --git a/module/zfs/zfs_replay.c b/module/zfs/zfs_replay.c
index 09c7be853..2e0af60f6 100644
--- a/module/zfs/zfs_replay.c
+++ b/module/zfs/zfs_replay.c
@@ -309,6 +309,8 @@ zfs_replay_create_acl(void *arg1, void *arg2, boolean_t byteswap)
 	uint64_t dnodesize;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lracl));
+
 	txtype = (lr->lr_common.lrc_txtype & ~TX_CI);
 	if (byteswap) {
 		byteswap_uint64_array(lracl, sizeof (*lracl));
@@ -470,6 +472,8 @@ zfs_replay_create(void *arg1, void *arg2, boolean_t byteswap)
 	uint64_t dnodesize;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr));
+
 	txtype = (lr->lr_common.lrc_txtype & ~TX_CI);
 	if (byteswap) {
 		byteswap_uint64_array(lr, sizeof (*lr));
@@ -613,6 +617,8 @@ zfs_replay_remove(void *arg1, void *arg2, boolean_t byteswap)
 	int error;
 	int vflg = 0;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -648,6 +654,8 @@ zfs_replay_link(void *arg1, void *arg2, boolean_t byteswap)
 	int error;
 	int vflg = 0;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -715,12 +723,14 @@ zfs_replay_rename(void *arg1, void *arg2, boolean_t byteswap)
 {
 	zfsvfs_t *zfsvfs = arg1;
 	lr_rename_t *lr = arg2;
-	char *sname = (char *)(lr + 1);	/* sname and tname follow lr_rename_t */
-	char *tname = sname + strlen(sname) + 1;
+
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr));
 
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
+	char *sname = (char *)(lr + 1);	/* sname and tname follow lr_rename_t */
+	char *tname = sname + strlen(sname) + 1;
 	return (do_zfs_replay_rename(zfsvfs, lr, sname, tname, 0, NULL));
 }
 
@@ -730,12 +740,14 @@ zfs_replay_rename_exchange(void *arg1, void *arg2, boolean_t byteswap)
 #ifdef __linux__
 	zfsvfs_t *zfsvfs = arg1;
 	lr_rename_t *lr = arg2;
-	char *sname = (char *)(lr + 1);	/* sname and tname follow lr_rename_t */
-	char *tname = sname + strlen(sname) + 1;
+
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr));
 
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
+	char *sname = (char *)(lr + 1);	/* sname and tname follow lr_rename_t */
+	char *tname = sname + strlen(sname) + 1;
 	return (do_zfs_replay_rename(zfsvfs, lr, sname, tname, RENAME_EXCHANGE,
 	    NULL));
 #else
@@ -750,14 +762,13 @@ zfs_replay_rename_whiteout(void *arg1, void *arg2, boolean_t byteswap)
 	zfsvfs_t *zfsvfs = arg1;
 	lr_rename_whiteout_t *lr = arg2;
 	int error;
-	/* sname and tname follow lr_rename_whiteout_t */
-	char *sname = (char *)(lr + 1);
-	char *tname = sname + strlen(sname) + 1;
 	/* For the whiteout file. */
 	xvattr_t xva;
 	uint64_t objid;
 	uint64_t dnodesize;
 
+	ASSERT3U(lr->lr_rename.lr_common.lrc_reclen, >, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -783,6 +794,9 @@ zfs_replay_rename_whiteout(void *arg1, void *arg2, boolean_t byteswap)
 	if (error)
 		return (error);
 
+	/* sname and tname follow lr_rename_whiteout_t */
+	char *sname = (char *)(lr + 1);
+	char *tname = sname + strlen(sname) + 1;
 	return (do_zfs_replay_rename(zfsvfs, &lr->lr_rename, sname, tname,
 	    RENAME_WHITEOUT, &xva.xva_vattr));
 #else
@@ -800,6 +814,8 @@ zfs_replay_write(void *arg1, void *arg2, boolean_t byteswap)
 	int error;
 	uint64_t eod, offset, length;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -863,6 +879,8 @@ zfs_replay_write2(void *arg1, void *arg2, boolean_t byteswap)
 	int error;
 	uint64_t end;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -910,6 +928,8 @@ zfs_replay_truncate(void *arg1, void *arg2, boolean_t byteswap)
 	flock64_t fl = {0};
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -940,6 +960,8 @@ zfs_replay_setattr(void *arg1, void *arg2, boolean_t byteswap)
 	int error;
 	void *start;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	xva_init(&xva);
 	if (byteswap) {
 		byteswap_uint64_array(lr, sizeof (*lr));
@@ -1002,6 +1024,9 @@ zfs_replay_setsaxattr(void *arg1, void *arg2, boolean_t byteswap)
 	size_t size;
 	int error = 0;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lr->lr_common.lrc_reclen, >, sizeof (*lr) + lr->lr_size);
+
 	ASSERT(spa_feature_is_active(zfsvfs->z_os->os_spa,
 	    SPA_FEATURE_ZILSAXATTR));
 	if (byteswap)
@@ -1079,6 +1104,10 @@ zfs_replay_acl_v0(void *arg1, void *arg2, boolean_t byteswap)
 	znode_t *zp;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr) +
+	    sizeof (ace_t) * lr->lr_aclcnt);
+
 	if (byteswap) {
 		byteswap_uint64_array(lr, sizeof (*lr));
 		zfs_oldace_byteswap(ace, lr->lr_aclcnt);
@@ -1124,6 +1153,9 @@ zfs_replay_acl(void *arg1, void *arg2, boolean_t byteswap)
 	znode_t *zp;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr) + lr->lr_acl_bytes);
+
 	if (byteswap) {
 		byteswap_uint64_array(lr, sizeof (*lr));
 		zfs_ace_byteswap(ace, lr->lr_acl_bytes, B_FALSE);
@@ -1171,6 +1203,10 @@ zfs_replay_clone_range(void *arg1, void *arg2, boolean_t byteswap)
 	znode_t *zp;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, offsetof(lr_clone_range_t,
+	    lr_bps[lr->lr_nbps]));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index a11886136..37fb792f5 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -522,6 +522,7 @@ zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
 			lr_t *lr = (lr_t *)lrp;
 			reclen = lr->lrc_reclen;
 			ASSERT3U(reclen, >=, sizeof (lr_t));
+			ASSERT3U(reclen, <=, end - lrp);
 			if (lr->lrc_seq > claim_lr_seq) {
 				arc_buf_destroy(abuf, &abuf);
 				goto done;
@@ -604,7 +605,7 @@ zil_claim_write(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t first_txg)
 	lr_write_t *lr = (lr_write_t *)lrc;
 	int error;
 
-	ASSERT(lrc->lrc_txtype == TX_WRITE);
+	ASSERT3U(lrc->lrc_reclen, >=, sizeof (*lr));
 
 	/*
 	 * If the block is not readable, don't claim it.  This can happen
@@ -631,7 +632,9 @@ zil_claim_clone_range(zilog_t *zilog, const lr_t *lrc, void *tx)
 	spa_t *spa;
 	uint_t ii;
 
-	ASSERT(lrc->lrc_txtype == TX_CLONE_RANGE);
+	ASSERT3U(lrc->lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lrc->lrc_reclen, >=, offsetof(lr_clone_range_t,
+	    lr_bps[lr->lr_nbps]));
 
 	if (tx == NULL) {
 		return (0);
@@ -691,7 +694,7 @@ zil_free_write(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t claim_txg)
 	lr_write_t *lr = (lr_write_t *)lrc;
 	blkptr_t *bp = &lr->lr_blkptr;
 
-	ASSERT(lrc->lrc_txtype == TX_WRITE);
+	ASSERT3U(lrc->lrc_reclen, >=, sizeof (*lr));
 
 	/*
 	 * If we previously claimed it, we need to free it.
@@ -712,7 +715,9 @@ zil_free_clone_range(zilog_t *zilog, const lr_t *lrc, void *tx)
 	spa_t *spa;
 	uint_t ii;
 
-	ASSERT(lrc->lrc_txtype == TX_CLONE_RANGE);
+	ASSERT3U(lrc->lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lrc->lrc_reclen, >=, offsetof(lr_clone_range_t,
+	    lr_bps[lr->lr_nbps]));
 
 	if (tx == NULL) {
 		return (0);
@@ -1794,6 +1799,7 @@ zil_lwb_write_issue(zilog_t *zilog, lwb_t *lwb)
 	    itx = list_next(&lwb->lwb_itxs, itx))
 		zil_lwb_commit(zilog, lwb, itx);
 	lwb->lwb_nused = lwb->lwb_nfilled;
+	ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_nmax);
 
 	lwb->lwb_root_zio = zio_root(spa, zil_lwb_flush_vdevs_done, lwb,
 	    ZIO_FLAG_CANFAIL);
@@ -2023,13 +2029,16 @@ zil_lwb_assign(zilog_t *zilog, lwb_t *lwb, itx_t *itx, list_t *ilwbs)
 		return (lwb);
 	}
 
+	reclen = lr->lrc_reclen;
 	if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) {
+		ASSERT3U(reclen, ==, sizeof (lr_write_t));
 		dlen = P2ROUNDUP_TYPED(
 		    lrw->lr_length, sizeof (uint64_t), uint64_t);
 	} else {
+		ASSERT3U(reclen, >=, sizeof (lr_t));
 		dlen = 0;
 	}
-	reclen = lr->lrc_reclen;
+	ASSERT3U(reclen, <=, zil_max_log_data(zilog, 0));
 	zilog->zl_cur_used += (reclen + dlen);
 
 cont:
@@ -2048,19 +2057,19 @@ cont:
 		if (lwb == NULL)
 			return (NULL);
 		lwb_sp = lwb->lwb_nmax - lwb->lwb_nused;
-
-		/*
-		 * There must be enough space in the new, empty log block to
-		 * hold reclen.  For WR_COPIED, we need to fit the whole
-		 * record in one block, and reclen is the header size + the
-		 * data size. For WR_NEED_COPY, we can create multiple
-		 * records, splitting the data into multiple blocks, so we
-		 * only need to fit one word of data per block; in this case
-		 * reclen is just the header size (no data).
-		 */
-		ASSERT3U(reclen + MIN(dlen, sizeof (uint64_t)), <=, lwb_sp);
 	}
 
+	/*
+	 * There must be enough space in the log block to hold reclen.
+	 * For WR_COPIED, we need to fit the whole record in one block,
+	 * and reclen is the write record header size + the data size.
+	 * For WR_NEED_COPY, we can create multiple records, splitting
+	 * the data into multiple blocks, so we only need to fit one
+	 * word of data per block; in this case reclen is just the header
+	 * size (no data).
+	 */
+	ASSERT3U(reclen + MIN(dlen, sizeof (uint64_t)), <=, lwb_sp);
+
 	dnow = MIN(dlen, lwb_sp - reclen);
 	if (dlen > dnow) {
 		ASSERT3U(lr->lrc_txtype, ==, TX_WRITE);
@@ -2236,7 +2245,9 @@ zil_itx_create(uint64_t txtype, size_t olrsize)
 	size_t itxsize, lrsize;
 	itx_t *itx;
 
+	ASSERT3U(olrsize, >=, sizeof (lr_t));
 	lrsize = P2ROUNDUP_TYPED(olrsize, sizeof (uint64_t), size_t);
+	ASSERT3U(lrsize, >=, olrsize);
 	itxsize = offsetof(itx_t, itx_lr) + lrsize;
 
 	itx = zio_data_buf_alloc(itxsize);
@@ -2255,6 +2266,10 @@ zil_itx_create(uint64_t txtype, size_t olrsize)
 static itx_t *
 zil_itx_clone(itx_t *oitx)
 {
+	ASSERT3U(oitx->itx_size, >=, sizeof (itx_t));
+	ASSERT3U(oitx->itx_size, ==,
+	    offsetof(itx_t, itx_lr) + oitx->itx_lr.lrc_reclen);
+
 	itx_t *itx = zio_data_buf_alloc(oitx->itx_size);
 	memcpy(itx, oitx, oitx->itx_size);
 	itx->itx_callback = NULL;
@@ -2265,6 +2280,9 @@ zil_itx_clone(itx_t *oitx)
 void
 zil_itx_destroy(itx_t *itx)
 {
+	ASSERT3U(itx->itx_size, >=, sizeof (itx_t));
+	ASSERT3U(itx->itx_lr.lrc_reclen, ==,
+	    itx->itx_size - offsetof(itx_t, itx_lr));
 	IMPLY(itx->itx_lr.lrc_txtype == TX_COMMIT, itx->itx_callback == NULL);
 	IMPLY(itx->itx_callback != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT);
 
@@ -2348,7 +2366,7 @@ void
 zil_remove_async(zilog_t *zilog, uint64_t oid)
 {
 	uint64_t otxg, txg;
-	itx_async_node_t *ian;
+	itx_async_node_t *ian, ian_search;
 	avl_tree_t *t;
 	avl_index_t where;
 	list_t clean_list;
@@ -2375,7 +2393,8 @@ zil_remove_async(zilog_t *zilog, uint64_t oid)
 		 * Locate the object node and append its list.
 		 */
 		t = &itxg->itxg_itxs->i_async_tree;
-		ian = avl_find(t, &oid, &where);
+		ian_search.ia_foid = oid;
+		ian = avl_find(t, &ian_search, &where);
 		if (ian != NULL)
 			list_move_tail(&clean_list, &ian->ia_list);
 		mutex_exit(&itxg->itxg_lock);
@@ -2573,7 +2592,7 @@ void
 zil_async_to_sync(zilog_t *zilog, uint64_t foid)
 {
 	uint64_t otxg, txg;
-	itx_async_node_t *ian;
+	itx_async_node_t *ian, ian_search;
 	avl_tree_t *t;
 	avl_index_t where;
 
@@ -2603,7 +2622,8 @@ zil_async_to_sync(zilog_t *zilog, uint64_t foid)
 		 */
 		t = &itxg->itxg_itxs->i_async_tree;
 		if (foid != 0) {
-			ian = avl_find(t, &foid, &where);
+			ian_search.ia_foid = foid;
+			ian = avl_find(t, &ian_search, &where);
 			if (ian != NULL) {
 				list_move_tail(&itxg->itxg_itxs->i_sync_list,
 				    &ian->ia_list);
diff --git a/module/zfs/zio_checksum.c b/module/zfs/zio_checksum.c
index 9de515e87..e511b31fe 100644
--- a/module/zfs/zio_checksum.c
+++ b/module/zfs/zio_checksum.c
@@ -363,11 +363,14 @@ zio_checksum_compute(zio_t *zio, enum zio_checksum checksum,
 			zil_chain_t zilc;
 			abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t));
 
-			size = P2ROUNDUP_TYPED(zilc.zc_nused, ZIL_MIN_BLKSZ,
-			    uint64_t);
+			uint64_t nused = P2ROUNDUP_TYPED(zilc.zc_nused,
+			    ZIL_MIN_BLKSZ, uint64_t);
+			ASSERT3U(size, >=, nused);
+			size = nused;
 			eck = zilc.zc_eck;
 			eck_offset = offsetof(zil_chain_t, zc_eck);
 		} else {
+			ASSERT3U(size, >=, sizeof (zio_eck_t));
 			eck_offset = size - sizeof (zio_eck_t);
 			abd_copy_to_buf_off(&eck, abd, eck_offset,
 			    sizeof (zio_eck_t));
@@ -448,12 +451,13 @@ zio_checksum_error_impl(spa_t *spa, const blkptr_t *bp,
 				return (SET_ERROR(ECKSUM));
 			}
 
-			if (nused > size) {
+			nused = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t);
+			if (size < nused)
 				return (SET_ERROR(ECKSUM));
-			}
-
-			size = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t);
+			size = nused;
 		} else {
+			if (size < sizeof (zio_eck_t))
+				return (SET_ERROR(ECKSUM));
 			eck_offset = size - sizeof (zio_eck_t);
 			abd_copy_to_buf_off(&eck, abd, eck_offset,
 			    sizeof (zio_eck_t));
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index 53dcb4dee..91b2d9fcb 100644
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -417,6 +417,8 @@ zvol_replay_truncate(void *arg1, void *arg2, boolean_t byteswap)
 	lr_truncate_t *lr = arg2;
 	uint64_t offset, length;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -453,6 +455,8 @@ zvol_replay_write(void *arg1, void *arg2, boolean_t byteswap)
 	dmu_tx_t *tx;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+
 	if (byteswap)
 		byteswap_uint64_array(lr, sizeof (*lr));
 
@@ -506,6 +510,10 @@ zvol_replay_clone_range(void *arg1, void *arg2, boolean_t byteswap)
 	uint_t ii;
 	int error;
 
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, sizeof (*lr));
+	ASSERT3U(lr->lr_common.lrc_reclen, >=, offsetof(lr_clone_range_t,
+	    lr_bps[lr->lr_nbps]));
+
 	dmu_objset_name(os, name);
 	cmn_err(CE_WARN, "ZFS dropping block cloning transaction for %s.",
 	    name);