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From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: paul@paul-moore.com, casey@schaufler-ca.com, omosnace@redhat.com,
	john.johansen@canonical.com, kpsingh@kernel.org
Cc: bpf@vger.kernel.org, linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v2 1/2] lsm: Clarify documentation of vm_enough_memory hook
Date: Mon, 28 Nov 2022 15:42:39 +0100	[thread overview]
Message-ID: <20221128144240.210110-2-roberto.sassu@huaweicloud.com> (raw)
In-Reply-To: <20221128144240.210110-1-roberto.sassu@huaweicloud.com>

From: Roberto Sassu <roberto.sassu@huawei.com>

include/linux/lsm_hooks.h reports the result of the LSM infrastructure to
the callers, not what LSMs should return to the LSM infrastructure.

Clarify that and add that if all LSMs return a positive value
__vm_enough_memory() will be called with cap_sys_admin set. If at least one
LSM returns 0 or negative, it will be called with cap_sys_admin cleared.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 include/linux/lsm_hooks.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 2831efebde69..c35e260efd8c 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1398,7 +1398,11 @@
  *	Check permissions for allocating a new virtual mapping.
  *	@mm contains the mm struct it is being added to.
  *	@pages contains the number of pages.
- *	Return 0 if permission is granted.
+ *	Return 0 if permission is granted by the LSM infrastructure to the
+ *	caller. If all LSMs return a positive value, __vm_enough_memory() will
+ *	be called with cap_sys_admin set. If at least one LSM returns 0 or
+ *	negative, __vm_enough_memory() will be called with cap_sys_admin
+ *	cleared.
  *
  * @ismaclabel:
  *	Check if the extended attribute specified by @name
-- 
2.25.1


  reply	other threads:[~2022-11-28 14:44 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-28 14:42 [PATCH v2 0/2] lsm: Improve LSM hooks documentation Roberto Sassu
2022-11-28 14:42 ` Roberto Sassu [this message]
2022-12-06 22:51   ` [PATCH v2 1/2] lsm: Clarify documentation of vm_enough_memory hook Paul Moore
2022-11-28 14:42 ` [PATCH v2 2/2] lsm: Add/fix return values in lsm_hooks.h and fix formatting Roberto Sassu
2022-12-07  0:21   ` Paul Moore
2022-12-07  7:58     ` Roberto Sassu
2022-12-07  9:17       ` Roberto Sassu
2022-12-07 19:34         ` Paul Moore
2022-12-08  9:29           ` Roberto Sassu
2022-12-08 21:59             ` Paul Moore
2022-12-08 22:18               ` Casey Schaufler
2022-11-29 16:48 ` [PATCH v2 0/2] lsm: Improve LSM hooks documentation Casey Schaufler

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