[PATCH] hfs_fill_super returns success even if no root inode
http://kernelfun.blogspot.com/2006/11/mokb-14-11-2006-linux-26x-selinux.html
mount that image...
fs: filesystem was not cleanly unmounted, running fsck.hfs is recommended. mounting read-only.
hfs: get root inode failed.
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000018
printing eip
...
EIP is at superblock_doinit+0x21/0x767
...
[] selinux_sb_kern_mount+0xc/0x4b
[] vfs_kern_mount+0x99/0xf6
[] do_kern_mount+0x2d/0x3e
[] do_mount+0x5fa/0x66d
[] sys_mount+0x77/0xae
[] syscall_call+0x7/0xb
DWARF2 unwinder stuck at syscall_call+0x7/0xb
hfs_fill_super() returns success even if
root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
or
sb->s_root = d_alloc_root(root_inode);
fails. This superblock finds its way to superblock_doinit() which does:
struct dentry *root = sb->s_root;
struct inode *inode = root->d_inode;
and boom. Need to make sure the error cases return an error, I think.
[akpm@osdl.org: return -ENOMEM on oom]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index d43b4fc..85b17b3 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -390,11 +390,13 @@
hfs_find_exit(&fd);
goto bail_no_root;
}
+ res = -EINVAL;
root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
hfs_find_exit(&fd);
if (!root_inode)
goto bail_no_root;
+ res = -ENOMEM;
sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root)
goto bail_iput;