This is a note to let you know that I've just added the patch titled smackfs: use __GFP_NOFAIL for smk_cipso_doi() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: smackfs-use-__gfp_nofail-for-smk_cipso_doi.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c5f98f98dbb6a540ba2c5b490e8154ba8c4b47fb Author: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Tue Oct 19 20:54:31 2021 +0900 smackfs: use __GFP_NOFAIL for smk_cipso_doi() [ 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@xxxxxxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index e26e7fbb89657..cf1f92a04359a 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -716,9 +716,7 @@ 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;