* Leaking path for search_binary_handler
@ 2018-09-25 17:27 ` Tong Zhang
0 siblings, 0 replies; 4+ messages in thread
From: Tong Zhang @ 2018-09-25 17:27 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, linux-security-module, wenbo.s
Kernel Version: 4.18.5
Problem Description:
search_binary_handler() should be called after setting bprm using prepare_binprm(),
and in prepare_binprm(), there’s a LSM hook security_bprm_set_creds(),
which can make a decision that binfmt cares.
We found a leaking path In fs/binfmt_misc.c:235, that don’t ask LSM’s decision.
- Tong
^ permalink raw reply [flat|nested] 4+ messages in thread
* Leaking path for search_binary_handler
@ 2018-09-25 17:27 ` Tong Zhang
0 siblings, 0 replies; 4+ messages in thread
From: Tong Zhang @ 2018-09-25 17:27 UTC (permalink / raw)
To: linux-security-module
Kernel Version: 4.18.5
Problem Description:
search_binary_handler() should be called after setting bprm using prepare_binprm(),
and in prepare_binprm(), there?s a LSM hook security_bprm_set_creds(),
which can make a decision that binfmt cares.
We found a leaking path In fs/binfmt_misc.c:235, that don?t ask LSM?s decision.
- Tong
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Leaking path for search_binary_handler
2018-09-25 17:27 ` Tong Zhang
@ 2018-09-26 12:59 ` Stephen Smalley
-1 siblings, 0 replies; 4+ messages in thread
From: Stephen Smalley @ 2018-09-26 12:59 UTC (permalink / raw)
To: Tong Zhang; +Cc: linux-fsdevel, linux-kernel, linux-security-module, wenbo.s
On 09/25/2018 01:27 PM, Tong Zhang wrote:
> Kernel Version: 4.18.5
>
> Problem Description:
>
> search_binary_handler() should be called after setting bprm using prepare_binprm(),
> and in prepare_binprm(), there’s a LSM hook security_bprm_set_creds(),
> which can make a decision that binfmt cares.
>
> We found a leaking path In fs/binfmt_misc.c:235, that don’t ask LSM’s decision.
Do you mean the MISC_FMT_CREDENTIALS case? That looks intentional to me,
as noted in the comment there, and as per
Documentation/admin-guide/binfmt-misc.rst's discussion of the
credentials flag.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Leaking path for search_binary_handler
@ 2018-09-26 12:59 ` Stephen Smalley
0 siblings, 0 replies; 4+ messages in thread
From: Stephen Smalley @ 2018-09-26 12:59 UTC (permalink / raw)
To: linux-security-module
On 09/25/2018 01:27 PM, Tong Zhang wrote:
> Kernel Version: 4.18.5
>
> Problem Description:
>
> search_binary_handler() should be called after setting bprm using prepare_binprm(),
> and in prepare_binprm(), there?s a LSM hook security_bprm_set_creds(),
> which can make a decision that binfmt cares.
>
> We found a leaking path In fs/binfmt_misc.c:235, that don?t ask LSM?s decision.
Do you mean the MISC_FMT_CREDENTIALS case? That looks intentional to me,
as noted in the comment there, and as per
Documentation/admin-guide/binfmt-misc.rst's discussion of the
credentials flag.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-09-26 12:59 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2018-09-25 17:27 Leaking path for search_binary_handler Tong Zhang
2018-09-25 17:27 ` Tong Zhang
2018-09-26 12:59 ` Stephen Smalley
2018-09-26 12:59 ` Stephen Smalley
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