linux-kernel - Re: [PATCH] vfs: fix IMA lockdep circular locking dependency

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120530205320.GX11775@ZenIV.linux.org.uk>
Date:	Wed, 30 May 2012 21:53:20 +0100
From:	Al Viro <viro@...IV.linux.org.uk>
To:	Mimi Zohar <zohar@...ux.vnet.ibm.com>
Cc:	Eric Paris <eparis@...isplace.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Mimi Zohar <zohar@...ibm.com>,
	linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] vfs: fix IMA lockdep circular locking dependency

On Wed, May 30, 2012 at 04:33:36PM -0400, Mimi Zohar wrote:
> On Wed, 2012-05-30 at 21:24 +0100, Al Viro wrote:
> > On Wed, May 30, 2012 at 03:42:47PM -0400, Eric Paris wrote:
> > > security_file_mmap() would pretty much only be used in do_mmap_pgoff()
> > > (or validate_mmap_request)
> > 
> > Callers, actually - the whole point is to lift it out of under ->mmap_sem.
> > The tricky part is reqprot vs. prot mess.
> 
> Linus already addressed it in the original patch, which I split into two
> as you suggested:
> 733559f - "security: move security_file_mmap() and rename to security_mmap_file()" 
> b3649e9 security: define and use the new security_mmap_addr() hook

Ehh...

* elf_map() should just be using vm_map/vm_unmap (see vfs.git#for-next)
* that goto out; in sys_mmap_pgooff() is an instant leak - you miss
fput() that way
* again, prot handling for !MMU case differs from MMU one.  Sure, we
can duplicate both, but it's getting seriously ugly ;-/
* while we are at it, checking address in validate_mmap_request() is
really odd, seeing that we have the only call to validate_mmap_request()
followed by
        /* we ignore the address hint */
        addr = 0;
        len = PAGE_ALIGN(len);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/