[0/6] fs/minix: fix syzbot bugs and set s_maxbytes

Message

Eric Biggers June 28, 2020, 6:08 a.m. UTC

This series fixes all syzbot bugs in the minix filesystem:

	KASAN: null-ptr-deref Write in get_block
	KASAN: use-after-free Write in get_block
	KASAN: use-after-free Read in get_block
	WARNING in inc_nlink
	KMSAN: uninit-value in get_block
	WARNING in drop_nlink

It also fixes the minix filesystem to set s_maxbytes correctly, so that
userspace sees the correct behavior when exceeding the max file size.

Al or Andrew: one of you will need to take these patches, since no one
is maintaining this filesystem.


Eric Biggers (6):
  fs/minix: check return value of sb_getblk()
  fs/minix: don't allow getting deleted inodes
  fs/minix: reject too-large maximum file size
  fs/minix: set s_maxbytes correctly
  fs/minix: fix block limit check for V1 filesystems
  fs/minix: remove expected error message in block_to_path()

 fs/minix/inode.c        | 42 +++++++++++++++++++++++++++++++++++++----
 fs/minix/itree_common.c |  8 +++++++-
 fs/minix/itree_v1.c     | 12 ++++++------
 fs/minix/itree_v2.c     | 13 ++++++-------
 fs/minix/minix.h        |  1 -
 5 files changed, 57 insertions(+), 19 deletions(-)

Comments

Eric Biggers July 7, 2020, 5:14 p.m. UTC | #1

On Sat, Jun 27, 2020 at 11:08:39PM -0700, Eric Biggers wrote:
> This series fixes all syzbot bugs in the minix filesystem:
> 
> 	KASAN: null-ptr-deref Write in get_block
> 	KASAN: use-after-free Write in get_block
> 	KASAN: use-after-free Read in get_block
> 	WARNING in inc_nlink
> 	KMSAN: uninit-value in get_block
> 	WARNING in drop_nlink
> 
> It also fixes the minix filesystem to set s_maxbytes correctly, so that
> userspace sees the correct behavior when exceeding the max file size.
> 
> Al or Andrew: one of you will need to take these patches, since no one
> is maintaining this filesystem.
> 

Andrew, any interest in taking these patches?

- Eric