gfs2: Always check inode size of inline inodes

Check if the inode size of stuffed (inline) inodes is within the allowed
range when reading inodes from disk (gfs2_dinode_in()).  This prevents
us from on-disk corruption.

The two checks in stuffed_readpage() and gfs2_unstuffer_page() that just
truncate inline data to the maximum allowed size don't actually make
sense, and they can be removed now as well.

Reported-by: syzbot+7bb81dfa9cda07d9cd9d@syzkaller.appspotmail.com
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 05bee80..e782b4f 100644 (file)
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -427,8 +427,6 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
                return error;
 
        kaddr = kmap_atomic(page);
-       if (dsize > gfs2_max_stuffed_size(ip))
-               dsize = gfs2_max_stuffed_size(ip);
        memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
        memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
        kunmap_atomic(kaddr);

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 3bdb2c6..e7537fd 100644 (file)
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -61,9 +61,6 @@ static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
                void *kaddr = kmap(page);
                u64 dsize = i_size_read(inode);
  
-               if (dsize > gfs2_max_stuffed_size(ip))
-                       dsize = gfs2_max_stuffed_size(ip);
-
                memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
                memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
                kunmap(page);

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index af69a1b..d78b61e 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -449,6 +449,9 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
        ip->i_depth = (u8)depth;
        ip->i_entries = be32_to_cpu(str->di_entries);
 
+       if (gfs2_is_stuffed(ip) && inode->i_size > gfs2_max_stuffed_size(ip))
+               goto corrupt;
+
        if (S_ISREG(inode->i_mode))
                gfs2_set_aops(inode);