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| author | Hugh Dickins <hughd@google.com> | 2012-10-08 07:32:51 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-21 20:27:57 +0400 |
| commit | 530258fceacd8c17075906c648c1ba20928c940b (patch) | |
| tree | 6adac17cf54efdc5e000c5c2b22fee2a59b4e6a8 /fs/isofs/export.c | |
| parent | fb2ca533f518dabf814c6aab3b7ce3c236959a68 (diff) | |
| download | linux-530258fceacd8c17075906c648c1ba20928c940b.tar.xz | |
tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking
commit 35c2a7f4908d404c9124c2efc6ada4640ca4d5d5 upstream.
Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(),
u64 inum = fid->raw[2];
which is unhelpfully reported as at the end of shmem_alloc_inode():
BUG: unable to handle kernel paging request at ffff880061cd3000
IP: [<ffffffff812190d0>] shmem_alloc_inode+0x40/0x40
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Call Trace:
[<ffffffff81488649>] ? exportfs_decode_fh+0x79/0x2d0
[<ffffffff812d77c3>] do_handle_open+0x163/0x2c0
[<ffffffff812d792c>] sys_open_by_handle_at+0xc/0x10
[<ffffffff83a5f3f8>] tracesys+0xe1/0xe6
Right, tmpfs is being stupid to access fid->raw[2] before validating that
fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may
fall at the end of a page, and the next page not be present.
But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being
careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and
could oops in the same way: add the missing fh_len checks to those.
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Sage Weil <sage@inktank.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/isofs/export.c')
| -rw-r--r-- | fs/isofs/export.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/isofs/export.c b/fs/isofs/export.c index dd4687ff30d0..516eb21895c6 100644 --- a/fs/isofs/export.c +++ b/fs/isofs/export.c @@ -179,7 +179,7 @@ static struct dentry *isofs_fh_to_parent(struct super_block *sb, { struct isofs_fid *ifid = (struct isofs_fid *)fid; - if (fh_type != 2) + if (fh_len < 2 || fh_type != 2) return NULL; return isofs_export_iget(sb, |