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authorHugh Dickins <hughd@google.com>2012-10-07 20:32:51 -0700
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-09 23:33:55 -0400
commit35c2a7f4908d404c9124c2efc6ada4640ca4d5d5 (patch)
tree4ef3fa1953b939fb4bfff935b3d351f76d97252b /fs/isofs
parent8e22cc88d68ca1a46d7d582938f979eb640ed30f (diff)
downloadlinaro-lsk-35c2a7f4908d404c9124c2efc6ada4640ca4d5d5.tar.gz
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/isofs')
-rw-r--r--fs/isofs/export.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/isofs/export.c b/fs/isofs/export.c
index 1d3804492aa..2b4f2358ead 100644
--- a/fs/isofs/export.c
+++ b/fs/isofs/export.c
@@ -175,7 +175,7 @@ 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,