Initialize dn_next_type[] in the dnode constructor

It seems nothing ensures that this array is zeroed when a dnode is freshly allocated, so in principle it retains the values from the previous allocation. In practice it seems to be the case that the fields should end up zeroed, but we can zero the field anyway for consistency. This was found using KMSAN. Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Alexander Motin <[email protected]> Signed-off-by: Mark Johnston <[email protected]> Closes openzfs#12383
tonyhutter · Sep 14, 2021 · ac573e3 · ac573e3
1 parent 99df200
commit ac573e3
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
@@ -129,6 +129,7 @@ dnode_cons(void *arg, void *unused, int kmflag)
 	zfs_refcount_create(&dn->dn_tx_holds);
 	list_link_init(&dn->dn_link);
 
+	bzero(&dn->dn_next_type[0], sizeof (dn->dn_next_type));
 	bzero(&dn->dn_next_nblkptr[0], sizeof (dn->dn_next_nblkptr));
 	bzero(&dn->dn_next_nlevels[0], sizeof (dn->dn_next_nlevels));
 	bzero(&dn->dn_next_indblkshift[0], sizeof (dn->dn_next_indblkshift));