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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
        Igor Zhbanov <i.zhbanov@omprussia.ru>,
        James Morris <jmorris@namei.org>,
        Kentaro Takeda <takedakn@nttdata.co.jp>,
        tomoyo-dev-en@lists.osdn.me, "Serge E. Hallyn" <serge@hallyn.com>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0545/1017] TOMOYO: fix __setup handlers return values
Date:   Tue,  5 Apr 2022 09:24:18 +0200
Message-Id: <20220405070410.464004240@linuxfoundation.org>
In-Reply-To: <20220405070354.155796697@linuxfoundation.org>
References: <20220405070354.155796697@linuxfoundation.org>
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From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit 39844b7e3084baecef52d1498b5fa81afa2cefa9 ]

__setup() handlers should return 1 if the parameter is handled.
Returning 0 causes the entire string to be added to init's
environment strings (limited to 32 strings), unnecessarily polluting it.

Using the documented strings "TOMOYO_loader=string1" and
"TOMOYO_trigger=string2" causes an Unknown parameter message:
  Unknown kernel command line parameters
    "BOOT_IMAGE=/boot/bzImage-517rc5 TOMOYO_loader=string1 \
     TOMOYO_trigger=string2", will be passed to user space.

and these strings are added to init's environment string space:
  Run /sbin/init as init process
    with arguments:
     /sbin/init
    with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc5
     TOMOYO_loader=string1
     TOMOYO_trigger=string2

With this change, these __setup handlers act as expected,
and init's environment is not polluted with these strings.

Fixes: 0e4ae0e0dec63 ("TOMOYO: Make several options configurable.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: James Morris <jmorris@namei.org>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: tomoyo-dev-en@lists.osdn.me
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/tomoyo/load_policy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/tomoyo/load_policy.c b/security/tomoyo/load_policy.c
index 3445ae6fd479..363b65be87ab 100644
--- a/security/tomoyo/load_policy.c
+++ b/security/tomoyo/load_policy.c
@@ -24,7 +24,7 @@ static const char *tomoyo_loader;
 static int __init tomoyo_loader_setup(char *str)
 {
 	tomoyo_loader = str;
-	return 0;
+	return 1;
 }
 
 __setup("TOMOYO_loader=", tomoyo_loader_setup);
@@ -64,7 +64,7 @@ static const char *tomoyo_trigger;
 static int __init tomoyo_trigger_setup(char *str)
 {
 	tomoyo_trigger = str;
-	return 0;
+	return 1;
 }
 
 __setup("TOMOYO_trigger=", tomoyo_trigger_setup);
-- 
2.34.1