aboutsummaryrefslogtreecommitdiffstats
path: root/fs/gfs2
diff options
context:
space:
mode:
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/gfs2
parent8e22cc88d68ca1a46d7d582938f979eb640ed30f (diff)
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/gfs2')
-rw-r--r--fs/gfs2/export.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
index e8ed6d4a618..4767774a5f3 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -161,6 +161,8 @@ static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
case GFS2_SMALL_FH_SIZE:
case GFS2_LARGE_FH_SIZE:
case GFS2_OLD_FH_SIZE:
+ if (fh_len < GFS2_SMALL_FH_SIZE)
+ return NULL;
this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
this.no_formal_ino |= be32_to_cpu(fh[1]);
this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
@@ -180,6 +182,8 @@ static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
switch (fh_type) {
case GFS2_LARGE_FH_SIZE:
case GFS2_OLD_FH_SIZE:
+ if (fh_len < GFS2_LARGE_FH_SIZE)
+ return NULL;
parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
parent.no_formal_ino |= be32_to_cpu(fh[5]);
parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;