BUG: using smp_processor_id() in preemptible code in tipc_crypto_xmit

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f4926d51 Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=137a899b100000
kernel config: https://syzkaller.appspot.com/x/.config?x=dcc6334acae363d4
dashboard link: https://syzkaller.appspot.com/bug?extid=263f8c0d007dc09b2dda
compiler: gcc (GCC) 10.1.0-syz 20200507

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+263f8c...@syzkaller.appspotmail.com

BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor.1/23385
caller is tipc_aead_tfm_next net/tipc/crypto.c:402 [inline]
caller is tipc_aead_encrypt net/tipc/crypto.c:639 [inline]
caller is tipc_crypto_xmit+0x80a/0x2790 net/tipc/crypto.c:1605
CPU: 1 PID: 23385 Comm: syz-executor.1 Not tainted 5.8.0-rc1-syzkaller #0
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+0x18f/0x20d lib/dump_stack.c:118
check_preemption_disabled+0x20d/0x220 lib/smp_processor_id.c:48
tipc_aead_tfm_next net/tipc/crypto.c:402 [inline]
tipc_aead_encrypt net/tipc/crypto.c:639 [inline]
tipc_crypto_xmit+0x80a/0x2790 net/tipc/crypto.c:1605
tipc_bearer_xmit_skb+0x180/0x3f0 net/tipc/bearer.c:523
tipc_enable_bearer+0xb1d/0xdc0 net/tipc/bearer.c:331
__tipc_nl_bearer_enable+0x2bf/0x390 net/tipc/bearer.c:995
tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:1003
genl_family_rcv_msg_doit net/netlink/genetlink.c:691 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:736 [inline]
genl_rcv_msg+0x61d/0x9e0 net/netlink/genetlink.c:753
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
genl_rcv+0x24/0x40 net/netlink/genetlink.c:764
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb19
Code: Bad RIP value.
RSP: 002b:00007fa3c4dc1c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000501c40 RCX: 000000000045cb19
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a19 R14: 00000000004ccf82 R15: 00007fa3c4dc26d4
tipc: Enabled bearer <eth:vlan1>, priority 10


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 4437dd6e Merge tag 'io_uring-5.8-2020-07-12' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13a4773f100000
kernel config: https://syzkaller.appspot.com/x/.config?x=66ad203c2bb6d8b

dashboard link: https://syzkaller.appspot.com/bug?extid=263f8c0d007dc09b2dda
compiler: gcc (GCC) 10.1.0-syz 20200507

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=132d41c0900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=147f114f100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+263f8c...@syzkaller.appspotmail.com

tipc: Started in network mode
tipc: Own node identity aaaaaaaaaa3a, cluster identity 4711
tipc: Enabled bearer <eth:macsec0>, priority 0
tipc: TX(aaaaaaaaaa3a): key initiating, rc 1!
BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor201/6801

caller is tipc_aead_tfm_next net/tipc/crypto.c:402 [inline]
caller is tipc_aead_encrypt net/tipc/crypto.c:639 [inline]
caller is tipc_crypto_xmit+0x80a/0x2790 net/tipc/crypto.c:1605

CPU: 0 PID: 6801 Comm: syz-executor201 Not tainted 5.8.0-rc4-syzkaller #0

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+0x18f/0x20d lib/dump_stack.c:118

check_preemption_disabled+0x128/0x130 lib/smp_processor_id.c:48

tipc_aead_tfm_next net/tipc/crypto.c:402 [inline]
tipc_aead_encrypt net/tipc/crypto.c:639 [inline]
tipc_crypto_xmit+0x80a/0x2790 net/tipc/crypto.c:1605
tipc_bearer_xmit_skb+0x180/0x3f0 net/tipc/bearer.c:523
tipc_enable_bearer+0xb1d/0xdc0 net/tipc/bearer.c:331
__tipc_nl_bearer_enable+0x2bf/0x390 net/tipc/bearer.c:995

__tipc_nl_compat_doit net/tipc/netlink_compat.c:361 [inline]
tipc_nl_compat_doit+0x440/0x640 net/tipc/netlink_compat.c:383
tipc_nl_compat_handle net/tipc/netlink_compat.c:1268 [inline]
tipc_nl_compat_recv+0x4ef/0xb40 net/tipc/netlink_compat.c:1311
genl_family_rcv_msg_doit net/netlink/genetlink.c:669 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:714 [inline]
genl_rcv_msg+0x61d/0x980 net/netlink/genetlink.c:731
netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
genl_rcv+0x24/0x40 net/netlink/genetlink.c:742

netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:672
____sys_sendmsg+0x6e8/0x810 net/socket.c:2352
___sys_sendmsg+0xf3/0x170 net/socket.c:2406
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2439

do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4476a9
Code: Bad RIP value.
RSP: 002b:00007fff2b6d5168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000000

[syzbot]

syzbot has bisected this issue to:

commit e1f32190cf7ddd55778b460e7d44af3f76529698
Author: Tuong Lien <tuong....@dektech.com.au>
Date: Fri Nov 8 05:05:12 2019 +0000

tipc: add support for AEAD key setting via netlink

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11b738a0900000
start commit: 11ba4688 Linux 5.8-rc5
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=13b738a0900000
console output: https://syzkaller.appspot.com/x/log.txt?x=15b738a0900000
kernel config: https://syzkaller.appspot.com/x/.config?x=e944500a36bc4d55
dashboard link: https://syzkaller.appspot.com/bug?extid=263f8c0d007dc09b2dda
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14000957100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12d30d67100000

Reported-by: syzbot+263f8c...@syzkaller.appspotmail.com
Fixes: e1f32190cf7d ("tipc: add support for AEAD key setting via netlink")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[syzbot]

syzbot suspects this issue was fixed by commit:

commit bb8872a1e6bc911869a729240781076ed950764b
Author: Tuong Lien <tuong....@dektech.com.au>
Date: Sat Aug 29 19:37:55 2020 +0000

tipc: fix using smp_processor_id() in preemptible

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=100f5bb8500000
start commit: 6a9dc5fd lib: Revert use of fallthrough pseudo-keyword in ..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=978db74cb30aa994
dashboard link: https://syzkaller.appspot.com/bug?extid=263f8c0d007dc09b2dda
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=131a8c96900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1747c605900000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: tipc: fix using smp_processor_id() in preemptible

[Dmitry Vyukov]