[0/8] cifs: Fix support for NFS-style reparse points

Message

Pali Rohár Sept. 28, 2024, 9:59 p.m. UTC

For NFS-style reparse points in the current Linux SMB client I found few
buffer overflows and then incompatibility issues related to char/block
devices and symlinks. In this patch series I'm addressing these issues.
I also located commits which introduced these issues, I put them into
Fixes lines of commit messages.

Test cases against Windows server which exports one directory over both
SMB and NFS protocols. On Linux is mounted that directory to /mnt/nfs
and /mnt/smb via different protocols.

  mknod /mnt/nfs/char c 1 3
  stat /mnt/smb/char
  mknod /mnt/nfs/block b 8 0
  stat /mnt/smb/block
  ln -s abc\\abc /mnt/nfs/symlink
  stat /mnt/smb/symlink
  ls -l /mnt/smb

ls -l or stat over SMB should show the same information about char, block
and symlink as over NFS. And vice-versa.

Please look and check the buffer overflow issue as these buffer lengths
are always nightmares to handle correctly.

Pali Rohár (8):
  smb: Update comments about some reparse point tags
  cifs: Remove intermediate object of failed create reparse call
  cifs: Fix parsing NFS-style char/block devices
  cifs: Fix creating NFS-style char/block devices
  cifs: Fix buffer overflow when parsing NFS reparse points
  cifs: Do not convert delimiter when parsing NFS-style symlinks
  cifs: Validate content of NFS reparse point buffer
  cifs: Rename posix to nfs in parse_reparse_posix() and
    reparse_posix_data

 fs/smb/client/cifsglob.h  |  2 +-
 fs/smb/client/cifspdu.h   |  2 +-
 fs/smb/client/reparse.c   | 53 +++++++++++++++++++++++++++++++--------
 fs/smb/client/reparse.h   | 12 ++++++---
 fs/smb/client/smb2inode.c | 21 ++++++++++++++--
 fs/smb/common/smb2pdu.h   |  2 +-
 fs/smb/common/smbfsctl.h  |  7 +++---
 7 files changed, 77 insertions(+), 22 deletions(-)