Subject: Re: [syzbot] [rdma?] possible deadlock in sock_set_reuseaddr

From: syzbot <[email-masked]>
Date: Fri, 08 Nov 2024 07:10:22 -0800

syzbot has found a reproducer for the following issue on:

HEAD commit:    2696e451dfb0 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=110a3d87980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ea5200d154f868aa
dashboard link: https://syzkaller.appspot.com/bug?extid=af5682e4f50cd6bce838
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=17f7cea7980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13bbee30580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d35511e1cf15/disk-2696e451.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a547f0432d8f/vmlinux-2696e451.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9d3fb709c982/bzImage-2696e451.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

iwpm_register_pid: Unable to send a nlmsg (client = 2)
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc6-syzkaller-01219-g2696e451dfb0 #0 Not tainted
------------------------------------------------------
syz-executor331/5847 is trying to acquire lock:
ffff888024303558 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1617 [inline]
ffff888024303558 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_set_reuseaddr+0x17/0x60 net/core/sock.c:781

but task is already holding lock:
ffffffff8fa64d48 (lock#7){+.+.}-{3:3}, at: cma_add_one+0x6bc/0xcd0 drivers/infiniband/core/cma.c:5354

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (lock#7){+.+.}-{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
       cma_init+0x1e/0x140 drivers/infiniband/core/cma.c:5438
       do_one_initcall+0x248/0x880 init/main.c:1269
       do_initcall_level+0x157/0x210 init/main.c:1331
       do_initcalls+0x3f/0x80 init/main.c:1347
       kernel_init_freeable+0x435/0x5d0 init/main.c:1580
       kernel_init+0x1d/0x2b0 init/main.c:1469
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (rtnl_mutex){+.+.}-{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
       do_ip_setsockopt+0x127d/0x3cd0 net/ipv4/ip_sockglue.c:1077
       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:2336
       __sys_setsockopt+0x1a2/0x250 net/socket.c:2359
       __do_sys_setsockopt net/socket.c:2368 [inline]
       __se_sys_setsockopt net/socket.c:2365 [inline]
       __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2365
       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: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:2216
       __do_sys_sendto net/socket.c:2228 [inline]
       __se_sys_sendto net/socket.c:2224 [inline]
       __x64_sys_sendto+0xde/0x100 net/socket.c:2224
       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: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
       lock_sock_nested+0x48/0x100 net/core/sock.c:3616
       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: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:729 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:744
       ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2609
       ___sys_sendmsg net/socket.c:2663 [inline]
       __sys_sendmsg+0x292/0x380 net/socket.c:2692
       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 --> rtnl_mutex --> lock#7

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#7);
                               lock(rtnl_mutex);
                               lock(lock#7);
  lock(sk_lock-AF_INET);

 *** DEADLOCK ***

6 locks held by syz-executor331/5847:
 #0: ffffffff9a7a1918 (&rdma_nl_types[idx].sem){.+.+}-{3:3}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline]
 #0: ffffffff9a7a1918 (&rdma_nl_types[idx].sem){.+.+}-{3:3}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 #0: ffffffff9a7a1918 (&rdma_nl_types[idx].sem){.+.+}-{3:3}, at: rdma_nl_rcv+0x32d/0x9e0 drivers/infiniband/core/netlink.c:259
 #1: ffffffff8fa50fb0 (link_ops_rwsem){++++}-{3:3}, at: nldev_newlink+0x42a/0x640 drivers/infiniband/core/nldev.c:1785
 #2: ffffffff8fa43bd0 (devices_rwsem){++++}-{3:3}, at: enable_device_and_get+0x12e/0x440 drivers/infiniband/core/device.c:1328
 #3: ffffffff8fa43ed0 (clients_rwsem){++++}-{3:3}, at: enable_device_and_get+0x196/0x440 drivers/infiniband/core/device.c:1336
 #4: ffff88807fc405d0 (&device->client_data_rwsem){++++}-{3:3}, at: add_client_context+0x4f4/0x8b0 drivers/infiniband/core/device.c:725
 #5: ffffffff8fa64d48 (lock#7){+.+.}-{3:3}, at: cma_add_one+0x6bc/0xcd0 drivers/infiniband/core/cma.c:5354

stack backtrace:
CPU: 0 UID: 0 PID: 5847 Comm: syz-executor331 Not tainted 6.12.0-rc6-syzkaller-01219-g2696e451dfb0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
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
 lock_sock_nested+0x48/0x100 net/core/sock.c:3616
 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: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:729 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:744
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2609
 ___sys_sendmsg net/socket.c:2663 [inline]
 __sys_sendmsg+0x292/0x380 net/socket.c:2692
 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: 0033:0x7f6a537db819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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:00007ffe43eb0c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6a53829482 RCX: 00007f6a537db819
RDX: 00000000200040c0 RSI: 00000000200004c0 RDI: 0000000000000005
RBP: 00007f6a53829460 R08: 0000555500000000 R09: 0000555500000000
R10: 0000555500000000 R11: 000000

---
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