* Re: [syzbot] [net?] possible deadlock in gtp_encap_enable_socket
[not found] <66f18d50.050a0220.c23dd.0012.GAE@google.com>
@ 2024-10-30 12:02 ` Pablo Neira Ayuso
2025-05-12 16:08 ` syzbot
1 sibling, 0 replies; 3+ messages in thread
From: Pablo Neira Ayuso @ 2024-10-30 12:02 UTC (permalink / raw)
To: syzbot
Cc: davem, edumazet, kuba, laforge, linux-kernel, netdev,
osmocom-net-gprs, pabeni, syzkaller-bugs, wenjia, jaka, alibuda,
tonylu, guwen
Cc'ing SMC maintainers.
syzkaller combining layer is a crazy way to find crashes.
I think this is a false possible lockdep considers smc->clcsock_release_lock
is a lock of the same class sk_lock-AF_INET.
this can be solved with lockdep_set_class in af_smc?
Thanks.
On Mon, Sep 23, 2024 at 08:46:24AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9410645520e9 Merge tag 'net-next-6.12' of git://git.kernel..
> git tree: net-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=15d39e9f980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=37c006d80708398d
> dashboard link: https://syzkaller.appspot.com/bug?extid=e953a8f3071f5c0a28fd
> 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=16215ca9980000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=110c6c27980000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/80466d230dfb/disk-94106455.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/ba253eabab42/vmlinux-94106455.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/569982fb6c88/bzImage-94106455.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e953a8f3071f5c0a28fd@syzkaller.appspotmail.com
>
> IPVS: Unknown mcast interface: macvlan0
> netlink: 8 bytes leftover after parsing attributes in process `syz-executor297'.
> netlink: 24 bytes leftover after parsing attributes in process `syz-executor297'.
> ======================================================
> WARNING: possible circular locking dependency detected
> 6.11.0-syzkaller-01458-g9410645520e9 #0 Not tainted
> ------------------------------------------------------
> syz-executor297/5243 is trying to acquire lock:
> ffff88801cf99158 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1609 [inline]
> ffff88801cf99158 (sk_lock-AF_INET){+.+.}-{0:0}, at: gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674
>
> but task is already holding lock:
> ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
> ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #2 (rtnl_mutex){+.+.}-{3:3}:
> lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
> __mutex_lock_common kernel/locking/mutex.c:608 [inline]
> __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
> start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761
> do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732
> nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
> smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064
> do_sock_setsockopt+0x3af/0x720 net/socket.c:2330
> __sys_setsockopt+0x1ae/0x250 net/socket.c:2353
> __do_sys_setsockopt net/socket.c:2362 [inline]
> __se_sys_setsockopt net/socket.c:2359 [inline]
> __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2359
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #1 (&smc->clcsock_release_lock){+.+.}-{3:3}:
> lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
> __mutex_lock_common kernel/locking/mutex.c:608 [inline]
> __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
> smc_switch_to_fallback+0x35/0xdb0 net/smc/af_smc.c:902
> smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2771
> sock_sendmsg_nosec net/socket.c:730 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:745
> ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603
> ___sys_sendmsg net/socket.c:2657 [inline]
> __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #0 (sk_lock-AF_INET){+.+.}-{0:0}:
> check_prev_add kernel/locking/lockdep.c:3133 [inline]
> check_prevs_add kernel/locking/lockdep.c:3252 [inline]
> validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
> __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
> lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
> lock_sock_nested+0x48/0x100 net/core/sock.c:3611
> lock_sock include/net/sock.h:1609 [inline]
> gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674
> gtp_encap_enable drivers/net/gtp.c:1707 [inline]
> gtp_newlink+0x589/0xf30 drivers/net/gtp.c:1511
> rtnl_newlink_create net/core/rtnetlink.c:3510 [inline]
> __rtnl_newlink net/core/rtnetlink.c:3730 [inline]
> rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743
> rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646
> netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
> netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
> sock_sendmsg_nosec net/socket.c:730 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:745
> ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603
> ___sys_sendmsg net/socket.c:2657 [inline]
> __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> other info that might help us debug this:
>
> Chain exists of:
> sk_lock-AF_INET --> &smc->clcsock_release_lock --> rtnl_mutex
>
> Possible unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(rtnl_mutex);
> lock(&smc->clcsock_release_lock);
> lock(rtnl_mutex);
> lock(sk_lock-AF_INET);
>
> *** DEADLOCK ***
>
> 1 lock held by syz-executor297/5243:
> #0: ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
> #0: ffffffff8fc88588 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643
>
> stack backtrace:
> CPU: 0 UID: 0 PID: 5243 Comm: syz-executor297 Not tainted 6.11.0-syzkaller-01458-g9410645520e9 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:93 [inline]
> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
> check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
> check_prev_add kernel/locking/lockdep.c:3133 [inline]
> check_prevs_add kernel/locking/lockdep.c:3252 [inline]
> validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
> __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
> lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
> lock_sock_nested+0x48/0x100 net/core/sock.c:3611
> lock_sock include/net/sock.h:1609 [inline]
> gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674
> gtp_encap_enable drivers/net/gtp.c:1707 [inline]
> gtp_newlink+0x589/0xf30 drivers/net/gtp.c:1511
> rtnl_newlink_create net/core/rtnetlink.c:3510 [inline]
> __rtnl_newlink net/core/rtnetlink.c:3730 [inline]
> rtnl_newlink+0x1591/0x20a0 net/core/rtnetlink.c:3743
> rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6646
> netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
> netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
> netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
> sock_sendmsg_nosec net/socket.c:730 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:745
> ____sys_sendmsg+0x525/0x7d0 net/socket.c:2603
> ___sys_sendmsg net/socket.c:2657 [inline]
> __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2686
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fed198844a9
> Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RS
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
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>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
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> If you attach or paste a git patch, syzbot will apply it before testing.
>
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>
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>
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [syzbot] [net?] possible deadlock in gtp_encap_enable_socket
[not found] <66f18d50.050a0220.c23dd.0012.GAE@google.com>
2024-10-30 12:02 ` [syzbot] [net?] possible deadlock in gtp_encap_enable_socket Pablo Neira Ayuso
@ 2025-05-12 16:08 ` syzbot
2025-05-12 22:10 ` Kuniyuki Iwashima
1 sibling, 1 reply; 3+ messages in thread
From: syzbot @ 2025-05-12 16:08 UTC (permalink / raw)
To: alibuda, danielyang32, danielyangkang, davem, edumazet, guwen,
hdanton, jaka, kuba, kuniyu, laforge, linux-kernel, linux-s390,
lkp, llvm, netdev, oe-kbuild-all, osmocom-net-gprs-bounces,
osmocom-net-gprs, pabeni, pablo, syzkaller-bugs, tonylu, wenjia
syzbot suspects this issue was fixed by commit:
commit 752e2217d789be2c6a6ac66554b981cd71cd9f31
Author: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Mon Apr 7 17:03:17 2025 +0000
smc: Fix lockdep false-positive for IPPROTO_SMC.
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=140462f4580000
start commit: 9410645520e9 Merge tag 'net-next-6.12' of git://git.kernel..
git tree: net-next
kernel config: https://syzkaller.appspot.com/x/.config?x=37c006d80708398d
dashboard link: https://syzkaller.appspot.com/bug?extid=e953a8f3071f5c0a28fd
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16215ca9980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=110c6c27980000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: smc: Fix lockdep false-positive for IPPROTO_SMC.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
^ permalink raw reply [flat|nested] 3+ messages in thread