Hi, I am Cc'ing SHARED MEMORY COMMUNICATIONS (SMC) SOCKETS maintainers. Similar issue already reported by syzkaller here: https://lore.kernel.org/netdev/ZyIgRmJUbnZpzXNV@calendula/T/#mf1f03a65108226102d8567c9fb6bab98c072444c related to smc->clcsock_release_lock. I think this is a false possible lockdep considers smc->clcsock_release_lock is a lock of the same class sk_lock-AF_INET. Could you please advise? Thanks. On Fri, Nov 01, 2024 at 05:20:27PM -0700, syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 6c52d4da1c74 Merge tag 'for-linus' of git://git.kernel.org.. > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12889630580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=672325e7ab17fdf7 > dashboard link: https://syzkaller.appspot.com/bug?extid=e929093395ec65f969c7 > 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=1788e187980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a4f2a7980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/70526f6a5c28/disk-6c52d4da.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/8ca3cd20d331/vmlinux-6c52d4da.xz > kernel image: https://storage.googleapis.com/syzbot-assets/9c4393fc9a08/bzImage-6c52d4da.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+e929093395ec65f969c7@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 6.12.0-rc5-syzkaller-00181-g6c52d4da1c74 #0 Not tainted > ------------------------------------------------------ > syz-executor158/5839 is trying to acquire lock: > ffffffff8fcd3448 (rtnl_mutex){+.+.}-{3:3}, at: start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761 > > but task is already holding lock: > ffff888034ac8aa8 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3056 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (&smc->clcsock_release_lock){+.+.}-{3:3}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > __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:729 [inline] > __sock_sendmsg+0x221/0x270 net/socket.c:744 > __sys_sendto+0x39b/0x4f0 net/socket.c:2214 > __do_sys_sendto net/socket.c:2226 [inline] > __se_sys_sendto net/socket.c:2222 [inline] > __x64_sys_sendto+0xde/0x100 net/socket.c:2222 > 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 (sk_lock-AF_INET){+.+.}-{0:0}: > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > lock_sock_nested+0x48/0x100 net/core/sock.c:3611 > do_ip_setsockopt+0x1a2d/0x3cd0 net/ipv4/ip_sockglue.c:1078 > ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417 > do_sock_setsockopt+0x3af/0x720 net/socket.c:2334 > __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 > __do_sys_setsockopt net/socket.c:2366 [inline] > __se_sys_setsockopt net/socket.c:2363 [inline] > __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 > 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 (rtnl_mutex){+.+.}-{3:3}: > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 > __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > __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:2334 > __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 > __do_sys_setsockopt net/socket.c:2366 [inline] > __se_sys_setsockopt net/socket.c:2363 [inline] > __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 > 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: > rtnl_mutex --> sk_lock-AF_INET --> &smc->clcsock_release_lock > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&smc->clcsock_release_lock); > lock(sk_lock-AF_INET); > lock(&smc->clcsock_release_lock); > lock(rtnl_mutex); > > *** DEADLOCK *** > > 1 lock held by syz-executor158/5839: > #0: ffff888034ac8aa8 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3056 > > stack backtrace: > CPU: 0 UID: 0 PID: 5839 Comm: syz-executor158 Not tainted 6.12.0-rc5-syzkaller-00181-g6c52d4da1c74 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 > check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 > __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 > __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:2334 > __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 > __do_sys_setsockopt net/socket.c:2366 [inline] > __se_sys_setsockopt net/socket.c:2363 [inline] > __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 > 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: 0033:0x7f468bc1c369 > 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 > RSP: 002b:00007ffe79331b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 > RAX: ffffffffffffffda RBX: 00007ffe79331ce8 RCX: 00007f468bc1c369 > RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000005 > RBP: 00007f468bc8f610 R08: 0000000000000018 R09: 00007ffe79331ce8 > R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000001 > R13: 00007ffe79331cd8 R14: 0000000000000001 R15: 0000000000000001 > </TASK> > IPVS: Unkn > > > --- > 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.
