From mboxrd@z Thu Jan 1 00:00:00 1970 From: john.johansen@canonical.com (John Johansen) Date: Sat, 1 Sep 2018 21:52:11 -0700 Subject: WARNING in apparmor_secid_to_secctx In-Reply-To: References: <000000000000c178e305749daba4@google.com> <45dda774-fd57-3e60-fb67-ad855f2360c9@canonical.com> Message-ID: <09def4f1-7dd8-ba41-139a-0c6f3be2db78@canonical.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On 09/01/2018 09:33 PM, Dmitry Vyukov wrote: > On Sat, Sep 1, 2018 at 11:18 AM, John Johansen > wrote: >> On 08/29/2018 07:17 PM, syzbot wrote: >>> Hello, >>> >>> syzbot found the following crash on: >>> >>> HEAD commit: 817e60a7a2bb Merge branch 'nfp-add-NFP5000-support' >>> git tree: net-next >>> console output: https://syzkaller.appspot.com/x/log.txt?x=1536d296400000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=531a917630d2a492 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=21016130b0580a9de3b5 >>> compiler: gcc (GCC) 8.0.1 20180413 (experimental) >>> >>> Unfortunately, I don't have any reproducer for this crash yet. >>> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>> Reported-by: syzbot+21016130b0580a9de3b5 at syzkaller.appspotmail.com >>> >> >> << snip >> >> >> Patch sent directly to syzbot for testing > > Hi John, > > What do you mean? syzbot has not received any test requests for this, > and it would reply within half an hour or so. Where is that patch? > Hrmmm strange I followed the web instruction and attached the patch to the reply. The patch is below, its also available at git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor 4.18-syzbot-secid --- >>From 22dad84baabf4174f11f5e9b34a05529084fa29c Mon Sep 17 00:00:00 2001 From: John Johansen Date: Sat, 1 Sep 2018 01:57:52 -0700 Subject: [PATCH] apparmor: fix apparmor_secid_to_secctx incorrect debug triggering WARN_ON apparmor_secid_to_secctx() has a bad debug statement tripping on a condition handle by the code. When kconfig SECURITY_APPARMOR_DEBUG is enabled the debug WARN_ON will trip when **secdata is NULL resulting in the following trace. ------------[ cut here ]------------ AppArmor WARN apparmor_secid_to_secctx: ((!secdata)): WARNING: CPU: 0 PID: 14826 at security/apparmor/secid.c:82 apparmor_secid_to_secctx+0x2b5/0x2f0 security/apparmor/secid.c:82 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 14826 Comm: syz-executor1 Not tainted 4.19.0-rc1+ #193 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 panic+0x238/0x4e7 kernel/panic.c:184 __warn.cold.8+0x163/0x1ba kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993 RIP: 0010:apparmor_secid_to_secctx+0x2b5/0x2f0 security/apparmor/secid.c:82 Code: c7 c7 40 66 58 87 e8 6a 6d 0f fe 0f 0b e9 6c fe ff ff e8 3e aa 44 fe 48 c7 c6 80 67 58 87 48 c7 c7 a0 65 58 87 e8 4b 6d 0f fe <0f> 0b e9 3f fe ff ff 48 89 df e8 fc a7 83 fe e9 ed fe ff ff bb f4 RSP: 0018:ffff8801ba1bed10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8801ba1beed0 RCX: ffffc9000227e000 RDX: 0000000000018482 RSI: ffffffff8163ac01 RDI: 0000000000000001 RBP: ffff8801ba1bed30 R08: ffff8801b80ec080 R09: ffffed003b603eca R10: ffffed003b603eca R11: ffff8801db01f657 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8801ba1beed0 security_secid_to_secctx+0x63/0xc0 security/security.c:1314 ctnetlink_secctx_size net/netfilter/nf_conntrack_netlink.c:621 [inline] ctnetlink_nlmsg_size net/netfilter/nf_conntrack_netlink.c:659 [inline] ctnetlink_conntrack_event+0x303/0x1470 net/netfilter/nf_conntrack_netlink.c:706 nf_conntrack_eventmask_report+0x55f/0x930 net/netfilter/nf_conntrack_ecache.c:151 nf_conntrack_event_report include/net/netfilter/nf_conntrack_ecache.h:112 [inline] nf_ct_delete+0x33c/0x5d0 net/netfilter/nf_conntrack_core.c:601 nf_ct_iterate_cleanup+0x48c/0x5e0 net/netfilter/nf_conntrack_core.c:1892 nf_ct_iterate_cleanup_net+0x23c/0x2d0 net/netfilter/nf_conntrack_core.c:1974 ctnetlink_flush_conntrack net/netfilter/nf_conntrack_netlink.c:1226 [inline] ctnetlink_del_conntrack+0x66c/0x850 net/netfilter/nf_conntrack_netlink.c:1258 nfnetlink_rcv_msg+0xd88/0x1070 net/netfilter/nfnetlink.c:228 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454 nfnetlink_rcv+0x1c0/0x4d0 net/netfilter/nfnetlink.c:560 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2114 __sys_sendmsg+0x11d/0x290 net/socket.c:2152 __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg net/socket.c:2159 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7bc6e03c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7bc6e046d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000020d65000 RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d4588 R14: 00000000004c8d5c R15: 0000000000000000 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: c092921219d2 ("apparmor: add support for mapping secids and using secctxes") Reported-by: syzbot+21016130b0580a9de3b5 at syzkaller.appspotmail.com Signed-off-by: John Johansen --- security/apparmor/secid.c | 1 - 1 file changed, 1 deletion(-) diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c index f2f22d00db18..4ccec1bcf6f5 100644 --- a/security/apparmor/secid.c +++ b/security/apparmor/secid.c @@ -79,7 +79,6 @@ int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) struct aa_label *label = aa_secid_to_label(secid); int len; - AA_BUG(!secdata); AA_BUG(!seclen); if (!label) -- 2.17.1