Illumos 5349 - verify that block pointer is plausible before reading

5349 verify that block pointer is plausible before reading
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Xin Li <delphij@FreeBSD.org>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References:
  https://www.illumos.org/issues/5349
  https://github.com/illumos/illumos-gate/commit/f63ab3d5

Porting notes:
* Several variable declarations were moved due to C style needs

Ported-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3373

include/sys/spa.h

@@ -830,6 +830,7 @@ extern boolean_t spa_has_slogs(spa_t *spa);
 extern boolean_t spa_is_root(spa_t *spa);
 extern boolean_t spa_writeable(spa_t *spa);
 extern boolean_t spa_has_pending_synctask(spa_t *spa);
+extern void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp);
 
 extern int spa_mode(spa_t *spa);
 extern uint64_t strtonum(const char *str, char **nptr);

module/zfs/zio.c

@@ -212,7 +212,7 @@ zio_buf_alloc(size_t size)
 {
 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
 
-	ASSERT3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
+	VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
 
 	return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE));
 }
@@ -228,7 +228,7 @@ zio_data_buf_alloc(size_t size)
 {
 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
 
-	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
+	VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
 
 	return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
 }
@@ -238,7 +238,7 @@ zio_buf_free(void *buf, size_t size)
 {
 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
 
-	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
+	VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
 
 	kmem_cache_free(zio_buf_cache[c], buf);
 }
@@ -248,7 +248,7 @@ zio_data_buf_free(void *buf, size_t size)
 {
 	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
 
-	ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
+	VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
 
 	kmem_cache_free(zio_data_buf_cache[c], buf);
 }
@@ -596,6 +596,90 @@ zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
 	return (zio_null(NULL, spa, NULL, done, private, flags));
 }
 
+void
+zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp)
+{
+	int i;
+
+	if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) {
+		zfs_panic_recover("blkptr at %p has invalid TYPE %llu",
+		    bp, (longlong_t)BP_GET_TYPE(bp));
+	}
+	if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS ||
+	    BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) {
+		zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu",
+		    bp, (longlong_t)BP_GET_CHECKSUM(bp));
+	}
+	if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS ||
+	    BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) {
+		zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu",
+		    bp, (longlong_t)BP_GET_COMPRESS(bp));
+	}
+	if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) {
+		zfs_panic_recover("blkptr at %p has invalid LSIZE %llu",
+		    bp, (longlong_t)BP_GET_LSIZE(bp));
+	}
+	if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) {
+		zfs_panic_recover("blkptr at %p has invalid PSIZE %llu",
+		    bp, (longlong_t)BP_GET_PSIZE(bp));
+	}
+
+	if (BP_IS_EMBEDDED(bp)) {
+		if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) {
+			zfs_panic_recover("blkptr at %p has invalid ETYPE %llu",
+			    bp, (longlong_t)BPE_GET_ETYPE(bp));
+		}
+	}
+
+	/*
+	 * Pool-specific checks.
+	 *
+	 * Note: it would be nice to verify that the blk_birth and
+	 * BP_PHYSICAL_BIRTH() are not too large.  However, spa_freeze()
+	 * allows the birth time of log blocks (and dmu_sync()-ed blocks
+	 * that are in the log) to be arbitrarily large.
+	 */
+	for (i = 0; i < BP_GET_NDVAS(bp); i++) {
+		uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]);
+		vdev_t *vd;
+		uint64_t offset, asize;
+		if (vdevid >= spa->spa_root_vdev->vdev_children) {
+			zfs_panic_recover("blkptr at %p DVA %u has invalid "
+			    "VDEV %llu",
+			    bp, i, (longlong_t)vdevid);
+		}
+		vd = spa->spa_root_vdev->vdev_child[vdevid];
+		if (vd == NULL) {
+			zfs_panic_recover("blkptr at %p DVA %u has invalid "
+			    "VDEV %llu",
+			    bp, i, (longlong_t)vdevid);
+		}
+		if (vd->vdev_ops == &vdev_hole_ops) {
+			zfs_panic_recover("blkptr at %p DVA %u has hole "
+			    "VDEV %llu",
+			    bp, i, (longlong_t)vdevid);
+
+		}
+		if (vd->vdev_ops == &vdev_missing_ops) {
+			/*
+			 * "missing" vdevs are valid during import, but we
+			 * don't have their detailed info (e.g. asize), so
+			 * we can't perform any more checks on them.
+			 */
+			continue;
+		}
+		offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
+		asize = DVA_GET_ASIZE(&bp->blk_dva[i]);
+		if (BP_IS_GANG(bp))
+			asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
+		if (offset + asize > vd->vdev_asize) {
+			zfs_panic_recover("blkptr at %p DVA %u has invalid "
+			    "OFFSET %llu",
+			    bp, i, (longlong_t)offset);
+		}
+	}
+}
+
 zio_t *
 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
     void *data, uint64_t size, zio_done_func_t *done, void *private,
@@ -603,6 +687,8 @@ zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 {
 	zio_t *zio;
 
+	zfs_blkptr_verify(spa, bp);
+
 	zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
 	    data, size, done, private,
 	    ZIO_TYPE_READ, priority, flags, NULL, 0, zb,