Revision 49054556289e8787501630b7c7a9d407da02e296 authored by Paolo Abeni on 29 September 2021, 09:59:17 UTC, committed by David S. Miller on 30 September 2021, 12:06:47 UTC
Syzkaller reported a false positive deadlock involving the nl socket lock and the subflow socket lock: MPTCP: kernel_bind error, err=-98 ============================================ WARNING: possible recursive locking detected 5.15.0-rc1-syzkaller #0 Not tainted -------------------------------------------- syz-executor998/6520 is trying to acquire lock: ffff8880795718a0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 but task is already holding lock: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-sk_lock-AF_INET); lock(k-sk_lock-AF_INET); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor998/6520: #0: ffffffff8d176c50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d176d08 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x3e0/0x580 net/netlink/genetlink.c:790 #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline] #2: ffff8880787c8c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x23/0x7b0 net/mptcp/protocol.c:2720 stack backtrace: CPU: 1 PID: 6520 Comm: syz-executor998 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline] check_deadlock kernel/locking/lockdep.c:2987 [inline] validate_chain kernel/locking/lockdep.c:3776 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 lock_sock_fast+0x36/0x100 net/core/sock.c:3229 mptcp_close+0x267/0x7b0 net/mptcp/protocol.c:2738 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 __sock_release net/socket.c:649 [inline] sock_release+0x87/0x1b0 net/socket.c:677 mptcp_pm_nl_create_listen_socket+0x238/0x2c0 net/mptcp/pm_netlink.c:900 mptcp_nl_cmd_add_addr+0x359/0x930 net/mptcp/pm_netlink.c:1170 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_no_sendpage+0x101/0x150 net/core/sock.c:2980 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504 kernel_sendpage net/socket.c:3501 [inline] sock_sendpage+0xe5/0x140 net/socket.c:1003 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xae9/0x1240 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f215cb69969 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc96bb3868 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f215cbad072 RCX: 00007f215cb69969 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc96bb3a08 R09: 00007ffc96bb3a08 R10: 0000000100000002 R11: 0000000000000246 R12: 00007ffc96bb387c R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 the problem originates from uncorrect lock annotation in the mptcp code and is only visible since commit 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations"), but is present since the port-based endpoint support initial implementation. This patch addresses the issue introducing a nested variant of lock_sock_fast() and using it in the relevant code path. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Fixes: 2dcb96bacce3 ("net: core: Correct the sock::sk_lock.owned lockdep annotations") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: syzbot+1dd53f7a89b299d59eaf@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
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bpf | ||
cgroup | ||
configs | ||
debug | ||
dma | ||
entry | ||
events | ||
gcov | ||
irq | ||
kcsan | ||
livepatch | ||
locking | ||
power | ||
printk | ||
rcu | ||
sched | ||
time | ||
trace | ||
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Kconfig.locks | -rw-r--r-- | 4.9 KB |
Kconfig.preempt | -rw-r--r-- | 4.4 KB |
Makefile | -rw-r--r-- | 5.2 KB |
acct.c | -rw-r--r-- | 15.4 KB |
async.c | -rw-r--r-- | 9.3 KB |
audit.c | -rw-r--r-- | 63.5 KB |
audit.h | -rw-r--r-- | 10.4 KB |
audit_fsnotify.c | -rw-r--r-- | 5.2 KB |
audit_tree.c | -rw-r--r-- | 25.5 KB |
audit_watch.c | -rw-r--r-- | 13.7 KB |
auditfilter.c | -rw-r--r-- | 34.1 KB |
auditsc.c | -rw-r--r-- | 71.7 KB |
backtracetest.c | -rw-r--r-- | 1.9 KB |
bounds.c | -rw-r--r-- | 751 bytes |
capability.c | -rw-r--r-- | 14.8 KB |
cfi.c | -rw-r--r-- | 8.1 KB |
compat.c | -rw-r--r-- | 6.8 KB |
configs.c | -rw-r--r-- | 2.0 KB |
context_tracking.c | -rw-r--r-- | 6.4 KB |
cpu.c | -rw-r--r-- | 65.0 KB |
cpu_pm.c | -rw-r--r-- | 6.1 KB |
crash_core.c | -rw-r--r-- | 11.6 KB |
crash_dump.c | -rw-r--r-- | 1.1 KB |
cred.c | -rw-r--r-- | 24.4 KB |
delayacct.c | -rw-r--r-- | 5.4 KB |
dma.c | -rw-r--r-- | 3.3 KB |
exec_domain.c | -rw-r--r-- | 1.1 KB |
exit.c | -rw-r--r-- | 44.8 KB |
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fail_function.c | -rw-r--r-- | 7.0 KB |
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freezer.c | -rw-r--r-- | 4.4 KB |
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gen_kheaders.sh | -rwxr-xr-x | 3.1 KB |
groups.c | -rw-r--r-- | 4.8 KB |
hung_task.c | -rw-r--r-- | 7.5 KB |
iomem.c | -rw-r--r-- | 4.7 KB |
irq_work.c | -rw-r--r-- | 4.9 KB |
jump_label.c | -rw-r--r-- | 21.4 KB |
kallsyms.c | -rw-r--r-- | 21.9 KB |
kcmp.c | -rw-r--r-- | 5.4 KB |
kcov.c | -rw-r--r-- | 27.7 KB |
kexec.c | -rw-r--r-- | 7.4 KB |
kexec_core.c | -rw-r--r-- | 31.2 KB |
kexec_elf.c | -rw-r--r-- | 11.4 KB |
kexec_file.c | -rw-r--r-- | 33.4 KB |
kexec_internal.h | -rw-r--r-- | 924 bytes |
kheaders.c | -rw-r--r-- | 1.6 KB |
kmod.c | -rw-r--r-- | 5.0 KB |
kprobes.c | -rw-r--r-- | 67.4 KB |
ksysfs.c | -rw-r--r-- | 6.3 KB |
kthread.c | -rw-r--r-- | 40.2 KB |
latencytop.c | -rw-r--r-- | 7.2 KB |
module-internal.h | -rw-r--r-- | 782 bytes |
module.c | -rw-r--r-- | 120.2 KB |
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notifier.c | -rw-r--r-- | 15.8 KB |
nsproxy.c | -rw-r--r-- | 12.8 KB |
padata.c | -rw-r--r-- | 27.4 KB |
panic.c | -rw-r--r-- | 18.2 KB |
params.c | -rw-r--r-- | 23.1 KB |
pid.c | -rw-r--r-- | 17.1 KB |
pid_namespace.c | -rw-r--r-- | 11.3 KB |
profile.c | -rw-r--r-- | 15.0 KB |
ptrace.c | -rw-r--r-- | 37.5 KB |
range.c | -rw-r--r-- | 3.0 KB |
reboot.c | -rw-r--r-- | 21.5 KB |
regset.c | -rw-r--r-- | 1.9 KB |
relay.c | -rw-r--r-- | 30.0 KB |
resource.c | -rw-r--r-- | 48.1 KB |
resource_kunit.c | -rw-r--r-- | 4.3 KB |
rseq.c | -rw-r--r-- | 10.1 KB |
scftorture.c | -rw-r--r-- | 19.7 KB |
scs.c | -rw-r--r-- | 2.8 KB |
seccomp.c | -rw-r--r-- | 61.9 KB |
signal.c | -rw-r--r-- | 122.5 KB |
smp.c | -rw-r--r-- | 33.5 KB |
smpboot.c | -rw-r--r-- | 11.7 KB |
smpboot.h | -rw-r--r-- | 640 bytes |
softirq.c | -rw-r--r-- | 23.5 KB |
stackleak.c | -rw-r--r-- | 3.6 KB |
stacktrace.c | -rw-r--r-- | 9.6 KB |
static_call.c | -rw-r--r-- | 12.5 KB |
stop_machine.c | -rw-r--r-- | 17.8 KB |
sys.c | -rw-r--r-- | 63.1 KB |
sys_ni.c | -rw-r--r-- | 10.1 KB |
sysctl-test.c | -rw-r--r-- | 10.7 KB |
sysctl.c | -rw-r--r-- | 81.1 KB |
task_work.c | -rw-r--r-- | 4.6 KB |
taskstats.c | -rw-r--r-- | 15.2 KB |
test_kprobes.c | -rw-r--r-- | 5.9 KB |
torture.c | -rw-r--r-- | 25.3 KB |
tracepoint.c | -rw-r--r-- | 20.3 KB |
tsacct.c | -rw-r--r-- | 4.7 KB |
ucount.c | -rw-r--r-- | 7.6 KB |
uid16.c | -rw-r--r-- | 5.1 KB |
uid16.h | -rw-r--r-- | 442 bytes |
umh.c | -rw-r--r-- | 15.1 KB |
up.c | -rw-r--r-- | 1.5 KB |
user-return-notifier.c | -rw-r--r-- | 1.3 KB |
user.c | -rw-r--r-- | 5.9 KB |
user_namespace.c | -rw-r--r-- | 35.3 KB |
usermode_driver.c | -rw-r--r-- | 4.3 KB |
utsname.c | -rw-r--r-- | 3.8 KB |
utsname_sysctl.c | -rw-r--r-- | 3.2 KB |
watch_queue.c | -rw-r--r-- | 16.4 KB |
watchdog.c | -rw-r--r-- | 20.1 KB |
watchdog_hld.c | -rw-r--r-- | 7.7 KB |
workqueue.c | -rw-r--r-- | 167.8 KB |
workqueue_internal.h | -rw-r--r-- | 2.4 KB |
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