smackfs: use __GFP_NOFAIL for smk_cipso_doi()

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
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>

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 9d853c0e55b849961dcbe993ad50f9bd67d38f1e..89989d28ffc5584d0f25bf36eac3b7624df5a437 100644 (file)
--- 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;