- Two stable@ fixes for the verity target's FEC support

- A stable@ fix for raid target's raid1 support (when no bitmap is used)
 
 - A 4.11 cache metadata v2 format fix to properly test blocks are clean
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Merge tag 'dm-4.11-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - two stable fixes for the verity target's FEC support

 - a stable fix for raid target's raid1 support (when no bitmap is used)

 - a 4.11 cache metadata v2 format fix to properly test blocks are clean

* tag 'dm-4.11-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm verity fec: fix bufio leaks
  dm raid: fix NULL pointer dereference for raid1 without bitmap
  dm cache metadata: fix metadata2 format's blocks_are_clean_separate_dirty
  dm verity fec: limit error correction recursion

drivers/md/dm-cache-metadata.c

@@ -932,7 +932,7 @@ static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
 	*result = true;
 
 	r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root,
-				   from_cblock(begin), &cmd->dirty_cursor);
+				   from_cblock(cmd->cache_blocks), &cmd->dirty_cursor);
 	if (r) {
 		DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__);
 		return r;
@@ -959,14 +959,16 @@ static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd,
 			return 0;
 		}
 
+		begin = to_cblock(from_cblock(begin) + 1);
+		if (begin == end)
+			break;
+
 		r = dm_bitset_cursor_next(&cmd->dirty_cursor);
 		if (r) {
 			DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__);
 			dm_bitset_cursor_end(&cmd->dirty_cursor);
 			return r;
 		}
-
-		begin = to_cblock(from_cblock(begin) + 1);
 	}
 
 	dm_bitset_cursor_end(&cmd->dirty_cursor);

drivers/md/dm-raid.c

@@ -3726,7 +3726,7 @@ static int raid_preresume(struct dm_target *ti)
 		return r;
 
 	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) */
-	if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) &&
+	if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
 	    mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)) {
 		r = bitmap_resize(mddev->bitmap, mddev->dev_sectors,
 				  to_bytes(rs->requested_bitmap_chunk_sectors), 0);

drivers/md/dm-verity-fec.c

@@ -146,8 +146,6 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
 		block = fec_buffer_rs_block(v, fio, n, i);
 		res = fec_decode_rs8(v, fio, block, &par[offset], neras);
 		if (res < 0) {
-			dm_bufio_release(buf);
-
 			r = res;
 			goto error;
 		}
@@ -172,6 +170,8 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
 done:
 	r = corrected;
 error:
+	dm_bufio_release(buf);
+
 	if (r < 0 && neras)
 		DMERR_LIMIT("%s: FEC %llu: failed to correct: %d",
 			    v->data_dev->name, (unsigned long long)rsb, r);
@@ -269,7 +269,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
 					  &is_zero) == 0) {
 			/* skip known zero blocks entirely */
 			if (is_zero)
-				continue;
+				goto done;
 
 			/*
 			 * skip if we have already found the theoretical
@@ -439,6 +439,13 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
 	if (!verity_fec_is_enabled(v))
 		return -EOPNOTSUPP;
 
+	if (fio->level >= DM_VERITY_FEC_MAX_RECURSION) {
+		DMWARN_LIMIT("%s: FEC: recursion too deep", v->data_dev->name);
+		return -EIO;
+	}
+
+	fio->level++;
+
 	if (type == DM_VERITY_BLOCK_TYPE_METADATA)
 		block += v->data_blocks;
 
@@ -470,7 +477,7 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
 	if (r < 0) {
 		r = fec_decode_rsb(v, io, fio, rsb, offset, true);
 		if (r < 0)
-			return r;
+			goto done;
 	}
 
 	if (dest)
@@ -480,6 +487,8 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io,
 		r = verity_for_bv_block(v, io, iter, fec_bv_copy);
 	}
 
+done:
+	fio->level--;
 	return r;
 }
 
@@ -520,6 +529,7 @@ void verity_fec_init_io(struct dm_verity_io *io)
 	memset(fio->bufs, 0, sizeof(fio->bufs));
 	fio->nbufs = 0;
 	fio->output = NULL;
+	fio->level = 0;
 }
 
 /*

drivers/md/dm-verity-fec.h

@@ -27,6 +27,9 @@
 #define DM_VERITY_FEC_BUF_MAX \
 	(1 << (PAGE_SHIFT - DM_VERITY_FEC_BUF_RS_BITS))
 
+/* maximum recursion level for verity_fec_decode */
+#define DM_VERITY_FEC_MAX_RECURSION	4
+
 #define DM_VERITY_OPT_FEC_DEV		"use_fec_from_device"
 #define DM_VERITY_OPT_FEC_BLOCKS	"fec_blocks"
 #define DM_VERITY_OPT_FEC_START		"fec_start"
@@ -58,6 +61,7 @@ struct dm_verity_fec_io {
 	unsigned nbufs;		/* number of buffers allocated */
 	u8 *output;		/* buffer for corrected output */
 	size_t output_pos;
+	unsigned level;		/* recursion level */
 };
 
 #ifdef CONFIG_DM_VERITY_FEC