oss-security - Re: CVE request: kernel: fuse: prevent fuse_put

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Date: Tue, 24 Nov 2009 13:06:51 -0500 (EST)
From: Josh Bressers <bressers@...hat.com>
To: oss-security@...ts.openwall.com
Cc: "Steven M. Christey" <coley@...us.mitre.org>
Subject: Re: CVE request: kernel: fuse: prevent
 fuse_put_request on invalid pointer

Please use CVE-2009-4021

Thanks.

-- 
    JB


----- "Eugene Teo" <eugeneteo@...nel.sg> wrote:

> "fuse_direct_io() has a loop where requests are allocated in each 
> iteration. if allocation fails, the loop is broken out and follows
> into 
> an unconditional fuse_put_request() on that invalid pointer."
> 
> Upstream commit:
> http://git.kernel.org/linus/f60311d5f7670d9539b424e4ed8b5c0872fc9e83
> 
> This can be triggered when the system is low on memory, and when the 
> fuse_request_alloc() function called from fuse_get_req() fails. The 
> fuse_put_request() function will then dereference the invalid pointer
> 
> returned, resulting in a kernel oops.
> 
> This was introduced in 413ef8cb (v2.6.14-rc1) and fixed in
> v2.6.32-rc7.
> 
> https://bugzilla.redhat.com/538734
> 
> Thanks, Eugene

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