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From:   Yue Hu <zbestahu@163.com>
To:     xiang@kernel.org, chao@kernel.org
Cc:     linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        zhangwen@coolpad.com, Yue Hu <huyue2@coolpad.com>
Subject: [PATCH] erofs: fix the unmapped access in z_erofs_fill_inode_lazy()
Date:   Tue,  4 Oct 2022 22:49:51 +0800
Message-Id: <20221004144951.31075-1-zbestahu@163.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Yue Hu <huyue2@coolpad.com>

Note that we are still accessing 'h_idata_size' and 'h_fragmentoff'
after calling erofs_put_metabuf(), that is not correct. Fix it.

Fixes: ab92184ff8f1 ("add on-disk compressed tail-packing inline support")
Fixes: b15b2e307c3a ("support on-disk compressed fragments data")
Signed-off-by: Yue Hu <huyue2@coolpad.com>
---
 fs/erofs/zmap.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 44c27ef39c43..1a15bbf18ba3 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -58,7 +58,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 	pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
 		    vi->xattr_isize, 8);
 	kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos),
-				   EROFS_KMAP_ATOMIC);
+				   EROFS_KMAP);
 	if (IS_ERR(kaddr)) {
 		err = PTR_ERR(kaddr);
 		goto out_unlock;
@@ -73,7 +73,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
 		vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
 		vi->z_tailextent_headlcn = 0;
-		goto unmap_done;
+		goto init_done;
 	}
 	vi->z_advise = le16_to_cpu(h->h_advise);
 	vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
@@ -105,10 +105,6 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		err = -EFSCORRUPTED;
 		goto unmap_done;
 	}
-unmap_done:
-	erofs_put_metabuf(&buf);
-	if (err)
-		goto out_unlock;
 
 	if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
 		struct erofs_map_blocks map = {
@@ -127,7 +123,7 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 			err = -EFSCORRUPTED;
 		}
 		if (err < 0)
-			goto out_unlock;
+			goto unmap_done;
 	}
 
 	if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
@@ -141,11 +137,14 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 					    EROFS_GET_BLOCKS_FINDTAIL);
 		erofs_put_metabuf(&map.buf);
 		if (err < 0)
-			goto out_unlock;
+			goto unmap_done;
 	}
+init_done:
 	/* paired with smp_mb() at the beginning of the function */
 	smp_mb();
 	set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
+unmap_done:
+	erofs_put_metabuf(&buf);
 out_unlock:
 	clear_and_wake_up_bit(EROFS_I_BL_Z_BIT, &vi->flags);
 	return err;
-- 
2.25.1