On Thu, Sep 19, 2024 at 9:23 AM syzbot <[email protected]> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: bdf56c7580d2 Merge tag 'slab-for-6.12' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12584b00580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4540f5bcdd31e3de > dashboard link: https://syzkaller.appspot.com/bug?extid=044fdf24e96093584232 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) > 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155cffc7980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ad24a9980000 > > Downloadable assets: > disk image: > https://storage.googleapis.com/syzbot-assets/cec9f3c675f1/disk-bdf56c75.raw.xz > vmlinux: > https://storage.googleapis.com/syzbot-assets/21e06ae5b159/vmlinux-bdf56c75.xz > kernel image: > https://storage.googleapis.com/syzbot-assets/1e936c954b8b/bzImage-bdf56c75.xz > > The issue was bisected to: > > commit 5f8d28f6d7d568dbbc8c5bce94894474c07afd4f > Author: Casey Schaufler <[email protected]> > Date: Wed Jul 10 21:32:26 2024 +0000 > > lsm: infrastructure management of the key security blob > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1124d69f980000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=1324d69f980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1524d69f980000
I just posted a patch which I believe should fix the problem, but I'd like to get Casey's ACK on it before submitting upstream as it does touch Smack code; lore link below: https://lore.kernel.org/linux-security-module/[email protected] ... in the meantime, I'm attaching the patch here so syzbot can verify that it solves the problem. #syz test -- paul-moore.com
selinux,smack: properly reference the LSM blob in security_watch_key() From: Paul Moore <[email protected]> Unfortunately when we migrated the lifecycle management of the key LSM blob to the LSM framework we forgot to convert the security_watch_key() callbacks for SELinux and Smack. This patch corrects this by making use of the selinux_key() and smack_key() helper functions respectively. This patch also removes some input checking in the Smack callback as it is no longer needed. Reported-by: [email protected] Fixes: 5f8d28f6d7d5 ("lsm: infrastructure management of the key security blob") Signed-off-by: Paul Moore <[email protected]> --- security/selinux/hooks.c | 2 +- security/smack/smack_lsm.c | 13 +++---------- 2 files changed, 4 insertions(+), 11 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 81fbfa5b80d4..67baa487cf7a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6720,7 +6720,7 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_KEY_NOTIFICATIONS static int selinux_watch_key(struct key *key) { - struct key_security_struct *ksec = key->security; + struct key_security_struct *ksec = selinux_key(key); u32 sid = current_sid(); return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index da0c2bffbd08..563fb404f659 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4629,16 +4629,9 @@ static int smack_watch_key(struct key *key) { struct smk_audit_info ad; struct smack_known *tkp = smk_of_current(); + struct smack_known **blob = smack_key(key); int rc; - if (key == NULL) - return -EINVAL; - /* - * If the key hasn't been initialized give it access so that - * it may do so. - */ - if (key->security == NULL) - return 0; /* * This should not occur */ @@ -4653,8 +4646,8 @@ static int smack_watch_key(struct key *key) ad.a.u.key_struct.key = key->serial; ad.a.u.key_struct.key_desc = key->description; #endif - rc = smk_access(tkp, key->security, MAY_READ, &ad); - rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc); + rc = smk_access(tkp, *blob, MAY_READ, &ad); + rc = smk_bu_note("key watch", tkp, *blob, MAY_READ, rc); return rc; } #endif /* CONFIG_KEY_NOTIFICATIONS */
