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| author | Hugh Dickins <hughd@google.com> | 2012-10-07 20:32:51 -0700 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-09 23:33:55 -0400 |
| commit | 35c2a7f4908d404c9124c2efc6ada4640ca4d5d5 (patch) | |
| tree | 4ef3fa1953b939fb4bfff935b3d351f76d97252b /fs/reiserfs | |
| parent | 8e22cc88d68ca1a46d7d582938f979eb640ed30f (diff) | |
| download | lwn-35c2a7f4908d404c9124c2efc6ada4640ca4d5d5.tar.gz lwn-35c2a7f4908d404c9124c2efc6ada4640ca4d5d5.zip | |
tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking
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>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/reiserfs')
| -rw-r--r-- | fs/reiserfs/inode.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 46485557cdc6..f27f01a98aa2 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -1573,8 +1573,10 @@ struct dentry *reiserfs_fh_to_dentry(struct super_block *sb, struct fid *fid, reiserfs_warning(sb, "reiserfs-13077", "nfsd/reiserfs, fhtype=%d, len=%d - odd", fh_type, fh_len); - fh_type = 5; + fh_type = fh_len; } + if (fh_len < 2) + return NULL; return reiserfs_get_dentry(sb, fid->raw[0], fid->raw[1], (fh_type == 3 || fh_type >= 5) ? fid->raw[2] : 0); @@ -1583,6 +1585,8 @@ struct dentry *reiserfs_fh_to_dentry(struct super_block *sb, struct fid *fid, struct dentry *reiserfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { + if (fh_type > fh_len) + fh_type = fh_len; if (fh_type < 4) return NULL; |