Merge tag 'for-5.19/dm-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Three fixes for invalid memory accesses discovered by using KASAN
  while running the lvm2 testsuite's dm-raid tests. Includes changes to
  MD's raid5.c given the dependency dm-raid has on the MD code"

* tag 'for-5.19/dm-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm raid: fix KASAN warning in raid5_add_disks
  dm raid: fix KASAN warning in raid5_remove_disk
  dm raid: fix accesses beyond end of raid member array

2 files changed, 23 insertions, 17 deletions

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 9526ccbedafb..80c9f7134e9b 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1001,12 +1001,13 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 static int validate_raid_redundancy(struct raid_set *rs)
 {
 	unsigned int i, rebuild_cnt = 0;
-	unsigned int rebuilds_per_group = 0, copies;
+	unsigned int rebuilds_per_group = 0, copies, raid_disks;
 	unsigned int group_size, last_group_start;
 
-	for (i = 0; i < rs->md.raid_disks; i++)
-		if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
-		    !rs->dev[i].rdev.sb_page)
+	for (i = 0; i < rs->raid_disks; i++)
+		if (!test_bit(FirstUse, &rs->dev[i].rdev.flags) &&
+		    ((!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
+		      !rs->dev[i].rdev.sb_page)))
 			rebuild_cnt++;
 
 	switch (rs->md.level) {
@@ -1046,8 +1047,9 @@ static int validate_raid_redundancy(struct raid_set *rs)
 		 *	    A	 A    B	   B	C
 		 *	    C	 D    D	   E	E
 		 */
+		raid_disks = min(rs->raid_disks, rs->md.raid_disks);
 		if (__is_raid10_near(rs->md.new_layout)) {
-			for (i = 0; i < rs->md.raid_disks; i++) {
+			for (i = 0; i < raid_disks; i++) {
 				if (!(i % copies))
 					rebuilds_per_group = 0;
 				if ((!rs->dev[i].rdev.sb_page ||
@@ -1070,10 +1072,10 @@ static int validate_raid_redundancy(struct raid_set *rs)
 		 * results in the need to treat the last (potentially larger)
 		 * set differently.
 		 */
-		group_size = (rs->md.raid_disks / copies);
-		last_group_start = (rs->md.raid_disks / group_size) - 1;
+		group_size = (raid_disks / copies);
+		last_group_start = (raid_disks / group_size) - 1;
 		last_group_start *= group_size;
-		for (i = 0; i < rs->md.raid_disks; i++) {
+		for (i = 0; i < raid_disks; i++) {
 			if (!(i % copies) && !(i > last_group_start))
 				rebuilds_per_group = 0;
 			if ((!rs->dev[i].rdev.sb_page ||
@@ -1588,7 +1590,7 @@ static sector_t __rdev_sectors(struct raid_set *rs)
 {
 	int i;
 
-	for (i = 0; i < rs->md.raid_disks; i++) {
+	for (i = 0; i < rs->raid_disks; i++) {
 		struct md_rdev *rdev = &rs->dev[i].rdev;
 
 		if (!test_bit(Journal, &rdev->flags) &&
@@ -3766,13 +3768,13 @@ static int raid_iterate_devices(struct dm_target *ti,
 	unsigned int i;
 	int r = 0;
 
-	for (i = 0; !r && i < rs->md.raid_disks; i++)
-		if (rs->dev[i].data_dev)
-			r = fn(ti,
-				 rs->dev[i].data_dev,
-				 0, /* No offset on data devs */
-				 rs->md.dev_sectors,
-				 data);
+	for (i = 0; !r && i < rs->raid_disks; i++) {
+		if (rs->dev[i].data_dev) {
+			r = fn(ti, rs->dev[i].data_dev,
+			       0, /* No offset on data devs */
+			       rs->md.dev_sectors, data);
+		}
+	}
 
 	return r;
 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 5d09256d7f81..20e53b167f81 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7933,7 +7933,7 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 	int err = 0;
 	int number = rdev->raid_disk;
 	struct md_rdev __rcu **rdevp;
-	struct disk_info *p = conf->disks + number;
+	struct disk_info *p;
 	struct md_rdev *tmp;
 
 	print_raid5_conf(conf);
@@ -7952,6 +7952,9 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 		log_exit(conf);
 		return 0;
 	}
+	if (unlikely(number >= conf->pool_size))
+		return 0;
+	p = conf->disks + number;
 	if (rdev == rcu_access_pointer(p->rdev))
 		rdevp = &p->rdev;
 	else if (rdev == rcu_access_pointer(p->replacement))
@@ -8062,6 +8065,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	 */
 	if (rdev->saved_raid_disk >= 0 &&
 	    rdev->saved_raid_disk >= first &&
+	    rdev->saved_raid_disk <= last &&
 	    conf->disks[rdev->saved_raid_disk].rdev == NULL)
 		first = rdev->saved_raid_disk;