From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot <syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 166/355] smackfs: use __GFP_NOFAIL for smk_cipso_doi()
Date:   Mon, 15 Nov 2021 18:01:30 +0100
Message-Id: <20211115165319.161819044@linuxfoundation.org>
In-Reply-To: <20211115165313.549179499@linuxfoundation.org>
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From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>

[ Upstream commit f91488ee15bd3cac467e2d6a361fc2d34d1052ae ]

syzbot is reporting kernel panic at smk_cipso_doi() due to memory
allocation fault injection [1]. The reason for need to use panic() was
not explained. But since no fix was proposed for 18 months, for now
let's use __GFP_NOFAIL for utilizing syzbot resource on other bugs.

Link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 [1]
Reported-by: syzbot <syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/smack/smackfs.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index cec3f56739dc2..fdf5f336f834a 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -693,9 +693,7 @@ static void smk_cipso_doi(void)
 		printk(KERN_WARNING "%s:%d remove rc = %d\n",
 		       __func__, __LINE__, rc);
 
-	doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL);
-	if (doip == NULL)
-		panic("smack:  Failed to initialize cipso DOI.\n");
+	doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL);
 	doip->map.std = NULL;
 	doip->doi = smk_cipso_doi_value;
 	doip->type = CIPSO_V4_MAP_PASS;
-- 
2.33.0