Re: KASAN: use-after-free Read in alloc_pid

From: Tetsuo Handa
Date: Tue Apr 10 2018 - 10:34:50 EST


syzbot wrote:
> syzbot has found reproducer for the following crash on upstream commit
> c18bb396d3d261ebbb4efbc05129c5d354c541e4 (Tue Apr 10 00:04:10 2018 +0000)
> Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
> syzbot dashboard link:
> https://syzkaller.appspot.com/bug?extid=7a1cff37dbbef9e7ba4c
>
While we are waiting for

rpc_pipefs: fix double-dput()
rpc_pipefs: deal with early sget() failures
kernfs: deal with early sget() failures
procfs: deal with early sget() failures
orangefs_kill_sb(): deal with allocation failures
nfsd_umount(): deal with early sget() failures
nfs: avoid double-free on early sget() failures
jffs2_kill_sb(): deal with failed allocations
hypfs_kill_super(): deal with failed allocations

in https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/log/?h=for-linus ,
I think the patch at

WARNING in kill_block_super
https://syzkaller.appspot.com/bug?id=588996a25a2587be2e3a54e8646728fb9cae44e7

is better.