Re: [syzbot] Re: KMSAN: uninit-value in gfs2_quota_init()

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Subject: Re: KMSAN: uninit-value in gfs2_quota_init()
Author: dmantipov@yandex.ru

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git b86545e02e8c22fb89218f29d381fa8e8b91d815

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index dbf1aede744c..85736135bcf5 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -299,6 +299,10 @@ static int gfs2_dir_read_data(struct gfs2_inode *ip, __be64 *buf,
 				goto fail;
 			BUG_ON(extlen < 1);
 			bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
+			if (IS_ERR(bh)) {
+				error = PTR_ERR(bh);
+				goto fail;
+			}
 		} else {
 			error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, 0, &bh);
 			if (error)
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index fea3efcc2f93..789294f4bf6f 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -512,7 +512,7 @@ int gfs2_meta_buffer(struct gfs2_inode *ip, u32 mtype, u64 num,
  * @dblock: the starting disk block
  * @extlen: the number of blocks in the extent
  *
- * returns: the first buffer in the extent
+ * returns: the first buffer in the extent or error number
  */
 
 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
@@ -521,6 +521,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 	struct buffer_head *first_bh, *bh;
 	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 			  sdp->sd_sb.sb_bsize_shift;
+	int ret;
 
 	BUG_ON(!extlen);
 
@@ -530,10 +531,15 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 		extlen = max_ra;
 
 	first_bh = gfs2_getbuf(gl, dblock, CREATE);
+	if (unlikely(!first_bh))
+		return ERR_PTR(-EINVAL);
 
 	if (buffer_uptodate(first_bh))
 		goto out;
-	bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
+
+	ret = bh_read(first_bh, REQ_META | REQ_PRIO);
+	if (unlikely(ret < 0))
+		return ERR_PTR(ret);
 
 	dblock++;
 	extlen--;
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 72b48f6f5561..d919edfb8dda 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -1427,8 +1427,10 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
 		}
 		error = -EIO;
 		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
-		if (!bh)
+		if (IS_ERR(bh)) {
+			error = PTR_ERR(bh);
 			goto fail;
+		}
 		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
 			goto fail_brelse;
 
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index f4fe7039f725..527353c36aa5 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -49,7 +49,7 @@ int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
 
 	*bh = gfs2_meta_ra(gl, dblock, extlen);
 
-	return error;
+	return IS_ERR(*bh) ? PTR_ERR(*bh) : 0;
 }
 
 int gfs2_revoke_add(struct gfs2_jdesc *jd, u64 blkno, unsigned int where)