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: [email protected] > > 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 [email protected]. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > 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: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup
