Message-ID: <6743ba8c.050a0220.1cc393.0050.GAE@google.com>
Date: Sun, 24 Nov 2024 15:45:16 -0800
From: syzbot <syzbot+e227429f6fa77945d7e4@...kaller.appspotmail.com>
To: davem@...emloft.net, dsahern@...nel.org, edumazet@...gle.com, 
	horms@...nel.org, kuba@...nel.org, linux-kernel@...r.kernel.org, 
	netdev@...r.kernel.org, pabeni@...hat.com, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [net?] possible deadlock in ip_mroute_setsockopt

syzbot has found a reproducer for the following issue on:

HEAD commit:    fcc79e1714e8 Merge tag 'net-next-6.13' of git://git.kernel..
git tree:       net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1448b75f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=275de99a754927af
dashboard link: https://syzkaller.appspot.com/bug?extid=e227429f6fa77945d7e4
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=175459c0580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10dc0ee8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8b723ddc7543/disk-fcc79e17.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ca8fd756cdfc/vmlinux-fcc79e17.xz
kernel image: https://storage.googleapis.com/syzbot-assets/778b3623fb8d/bzImage-fcc79e17.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e227429f6fa77945d7e4@...kaller.appspotmail.com

lo speed is unknown, defaulting to 1000
lo speed is unknown, defaulting to 1000
iwpm_register_pid: Unable to send a nlmsg (client = 2)
infiniband syz0: RDMA CMA: cma_listen_on_dev, error -98
======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Not tainted
------------------------------------------------------
syz-executor233/5845 is trying to acquire lock:
ffffffff8fce2348 (rtnl_mutex){+.+.}-{4:4}, at: ip_mroute_setsockopt+0x15b/0x1190 net/ipv4/ipmr.c:1370

but task is already holding lock:
ffff88807cfc0aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, 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:

-> #3 (&smc->clcsock_release_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       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:711 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:726
       __sys_sendto+0x363/0x4c0 net/socket.c:2197
       __do_sys_sendto net/socket.c:2204 [inline]
       __se_sys_sendto net/socket.c:2200 [inline]
       __x64_sys_sendto+0xde/0x100 net/socket.c:2200
       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

-> #2 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       lock_sock_nested+0x48/0x100 net/core/sock.c:3622
       lock_sock include/net/sock.h:1617 [inline]
       sock_set_reuseaddr+0x17/0x60 net/core/sock.c:781
       siw_create_listen+0x196/0xfe0 drivers/infiniband/sw/siw/siw_cm.c:1776
       iw_cm_listen+0x15e/0x230 drivers/infiniband/core/iwcm.c:585
       cma_iw_listen drivers/infiniband/core/cma.c:2668 [inline]
       rdma_listen+0x941/0xd60 drivers/infiniband/core/cma.c:3953
       cma_listen_on_dev+0x3e3/0x6f0 drivers/infiniband/core/cma.c:2727
       cma_add_one+0x7d7/0xcd0 drivers/infiniband/core/cma.c:5357
       add_client_context+0x536/0x8b0 drivers/infiniband/core/device.c:727
       enable_device_and_get+0x1e6/0x440 drivers/infiniband/core/device.c:1338
       ib_register_device+0x10d4/0x13e0 drivers/infiniband/core/device.c:1449
       siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline]
       siw_newlink+0x9d9/0xe50 drivers/infiniband/sw/siw/siw_main.c:452
       nldev_newlink+0x5c0/0x640 drivers/infiniband/core/nldev.c:1795
       rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
       rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259
       netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
       netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
       netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
       sock_sendmsg_nosec net/socket.c:711 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:726
       ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
       ___sys_sendmsg net/socket.c:2637 [inline]
       __sys_sendmsg+0x269/0x350 net/socket.c:2669
       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 (lock#7){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       cma_init+0x1e/0x140 drivers/infiniband/core/cma.c:5438
       do_one_initcall+0x248/0x880 init/main.c:1266
       do_initcall_level+0x157/0x210 init/main.c:1328
       do_initcalls+0x3f/0x80 init/main.c:1344
       kernel_init_freeable+0x435/0x5d0 init/main.c:1577
       kernel_init+0x1d/0x2b0 init/main.c:1466
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (rtnl_mutex){+.+.}-{4:4}:
       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+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       ip_mroute_setsockopt+0x15b/0x1190 net/ipv4/ipmr.c:1370
       do_ip_setsockopt+0x129f/0x3cd0 net/ipv4/ip_sockglue.c:948
       ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417
       smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064
       do_sock_setsockopt+0x3af/0x720 net/socket.c:2313
       __sys_setsockopt net/socket.c:2338 [inline]
       __do_sys_setsockopt net/socket.c:2344 [inline]
       __se_sys_setsockopt net/socket.c:2341 [inline]
       __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2341
       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-executor233/5845:
 #0: ffff88807cfc0aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3056

stack backtrace:
CPU: 0 UID: 0 PID: 5845 Comm: syz-executor233 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #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+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
 ip_mroute_setsockopt+0x15b/0x1190 net/ipv4/ipmr.c:1370
 do_ip_setsockopt+0x129f/0x3cd0 net/ipv4/ip_sockglue.c:948
 ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417
 smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064
 do_sock_setsockopt+0x3af/0x720 net/socket.c:2313
 __sys_setsockopt net/socket.c:2338 [inline]
 __do_sys_setsockopt net/socket.c:2344 [inline]
 __se_sys_setsockopt net/socket.c:2341 [inline]
 __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2341
 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: 0033:0x7f018ec824a9
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:00007ffe0c6806e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007ffe0c6808b8 RCX: 00007f018ec824a9
RDX: 00000000000000d2 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f018ecf5610 R08: 0000000000000000 R09: 00007ffe0c6808b8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe0c6808a8 R14: 0000000000000001 R15: 0


---
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.

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