syzbot

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WARNING: possible circular locking dependency detected
6.15.0-rc1-syzkaller-00325-g7cdabafc0012 #0 Not tainted
------------------------------------------------------
syz.0.2471/10399 is trying to acquire lock:
ffff8000887e3628 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:80

but task is already holding lock:
ffff00001e618aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0xd8/0x9ac net/smc/af_smc.c:3073

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x144/0x9d8 kernel/locking/mutex.c:746
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:798
       smc_switch_to_fallback+0x34/0x804 net/smc/af_smc.c:903
       smc_sendmsg+0xe4/0x8f8 net/smc/af_smc.c:2781
       sock_sendmsg_nosec net/socket.c:712 [inline]
       __sock_sendmsg+0xc8/0x168 net/socket.c:727
       __sys_sendto+0x1d8/0x26c net/socket.c:2180
       __do_sys_sendto net/socket.c:2187 [inline]
       __se_sys_sendto net/socket.c:2183 [inline]
       __arm64_sys_sendto+0xc0/0x134 net/socket.c:2183
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_sock_nested+0x38/0xe8 net/core/sock.c:3702
       lock_sock include/net/sock.h:1651 [inline]
       sockopt_lock_sock net/core/sock.c:1148 [inline]
       sockopt_lock_sock+0x58/0x74 net/core/sock.c:1139
       do_ip_setsockopt+0xe0/0x2354 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
       udp_setsockopt+0x20/0x44 net/ipv4/udp.c:3058
       sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3894
       do_sock_setsockopt+0x17c/0x354 net/socket.c:2296
       __sys_setsockopt+0xcc/0x144 net/socket.c:2321
       __do_sys_setsockopt net/socket.c:2327 [inline]
       __se_sys_setsockopt net/socket.c:2324 [inline]
       __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2324
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #0 (rtnl_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain kernel/locking/lockdep.c:3909 [inline]
       __lock_acquire+0x15f4/0x2314 kernel/locking/lockdep.c:5235
       lock_acquire kernel/locking/lockdep.c:5866 [inline]
       lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5823
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x144/0x9d8 kernel/locking/mutex.c:746
       mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:798
       rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:80
       ip_mroute_setsockopt+0xd4/0xe44 net/ipv4/ipmr.c:1396
       do_ip_setsockopt+0x1e0/0x2354 net/ipv4/ip_sockglue.c:948
       ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
       ipv6_setsockopt+0xf4/0x114 net/ipv6/ipv6_sockglue.c:988
       tcp_setsockopt+0x90/0xcc net/ipv4/tcp.c:4077
       sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3894
       smc_setsockopt+0x14c/0x9ac net/smc/af_smc.c:3081
       do_sock_setsockopt+0x17c/0x354 net/socket.c:2296
       __sys_setsockopt+0xcc/0x144 net/socket.c:2321
       __do_sys_setsockopt net/socket.c:2327 [inline]
       __se_sys_setsockopt net/socket.c:2324 [inline]
       __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2324
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
       el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:744
       el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

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.0.2471/10399:
 #0: ffff00001e618aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0xd8/0x9ac net/smc/af_smc.c:3073

stack backtrace:
CPU: 0 UID: 0 PID: 10399 Comm: syz.0.2471 Not tainted 6.15.0-rc1-syzkaller-00325-g7cdabafc0012 #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Call trace:
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xa4/0xf4 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x28c/0x370 kernel/locking/lockdep.c:2079
 check_noncircular+0x168/0x17c kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain kernel/locking/lockdep.c:3909 [inline]
 __lock_acquire+0x15f4/0x2314 kernel/locking/lockdep.c:5235
 lock_acquire kernel/locking/lockdep.c:5866 [inline]
 lock_acquire+0x310/0x38c kernel/locking/lockdep.c:5823
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x144/0x9d8 kernel/locking/mutex.c:746
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:798
 rtnl_lock+0x1c/0x28 net/core/rtnetlink.c:80
 ip_mroute_setsockopt+0xd4/0xe44 net/ipv4/ipmr.c:1396
 do_ip_setsockopt+0x1e0/0x2354 net/ipv4/ip_sockglue.c:948
 ip_setsockopt+0x34/0x9c net/ipv4/ip_sockglue.c:1417
 ipv6_setsockopt+0xf4/0x114 net/ipv6/ipv6_sockglue.c:988
 tcp_setsockopt+0x90/0xcc net/ipv4/tcp.c:4077
 sock_common_setsockopt+0x70/0xe0 net/core/sock.c:3894
 smc_setsockopt+0x14c/0x9ac net/smc/af_smc.c:3081
 do_sock_setsockopt+0x17c/0x354 net/socket.c:2296
 __sys_setsockopt+0xcc/0x144 net/socket.c:2321
 __do_sys_setsockopt net/socket.c:2327 [inline]
 __se_sys_setsockopt net/socket.c:2324 [inline]
 __arm64_sys_setsockopt+0xa4/0x100 net/socket.c:2324
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 UID: 0 PID: 10399 Comm: syz.0.2471 Not tainted 6.15.0-rc1-syzkaller-00325-g7cdabafc0012 #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Call trace:
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xdc/0xf4 lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x5a0/0x6ac lib/fault-inject.c:174
 should_fail+0x14/0x20 lib/fault-inject.c:184
 should_fail_usercopy+0x1c/0x28 lib/fault-inject-usercopy.c:37
 _inline_copy_to_user include/linux/uaccess.h:193 [inline]
 copy_to_user include/linux/uaccess.h:223 [inline]
 simple_read_from_buffer+0x94/0x1f0 fs/libfs.c:1121
 proc_fail_nth_read+0x160/0x248 fs/proc/base.c:1482
 vfs_read+0x18c/0x97c fs/read_write.c:568
 ksys_read+0xec/0x1d8 fs/read_write.c:713
 __do_sys_read fs/read_write.c:722 [inline]
 __se_sys_read fs/read_write.c:720 [inline]
 __arm64_sys_read+0x6c/0x9c fs/read_write.c:720
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x6c/0x258 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600