Merge tag 'jfs-5.18' of https://github.com/kleikamp/linux-shaggy

Pull jfs updates from Dave Kleikamp:
 "A couple bug fixes"

* tag 'jfs-5.18' of https://github.com/kleikamp/linux-shaggy:
  jfs: prevent NULL deref in diFree
  jfs: fix divide error in dbNextAG

fs/jfs/inode.c

@@ -146,12 +146,13 @@ void jfs_evict_inode(struct inode *inode)
 		dquot_initialize(inode);
 
 		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
+			struct inode *ipimap = JFS_SBI(inode->i_sb)->ipimap;
 			truncate_inode_pages_final(&inode->i_data);
 
 			if (test_cflag(COMMIT_Freewmap, inode))
 				jfs_free_zero_link(inode);
 
-			if (JFS_SBI(inode->i_sb)->ipimap)
+			if (ipimap && JFS_IP(ipimap)->i_imap)
 				diFree(inode);
 
 			/*

fs/jfs/jfs_dmap.c

@@ -148,6 +148,7 @@ static const s8 budtab[256] = {
  *	0	- success
  *	-ENOMEM	- insufficient memory
  *	-EIO	- i/o error
+ *	-EINVAL - wrong bmap data
  */
 int dbMount(struct inode *ipbmap)
 {
@@ -179,6 +180,12 @@ int dbMount(struct inode *ipbmap)
 	bmp->db_nfree = le64_to_cpu(dbmp_le->dn_nfree);
 	bmp->db_l2nbperpage = le32_to_cpu(dbmp_le->dn_l2nbperpage);
 	bmp->db_numag = le32_to_cpu(dbmp_le->dn_numag);
+	if (!bmp->db_numag) {
+		release_metapage(mp);
+		kfree(bmp);
+		return -EINVAL;
+	}
+
 	bmp->db_maxlevel = le32_to_cpu(dbmp_le->dn_maxlevel);
 	bmp->db_maxag = le32_to_cpu(dbmp_le->dn_maxag);
 	bmp->db_agpref = le32_to_cpu(dbmp_le->dn_agpref);