Re: INFO: task hung in lock_sock_nested
On Tue, Dec 12, 2017 at 05:47:34PM +0100, Dmitry Vyukov wrote: > On Sun, Dec 10, 2017 at 2:37 PM, syzbot >> wrote: > > Hello, > > > > syzkaller hit the following crash on > > 51e18a453f5f59a40c721d4aeab082b4e2e9fac6 > > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > > compiler: gcc (GCC) 7.1.1 20170620 > > .config is attached > > Raw console output is attached. > > > > Unfortunately, I don't have any reproducer for this bug yet. > > > > > > RDS: rds_bind could not find a transport for 172.20.1.187, load rds_tcp or > > rds_rdma? > > INFO: task syz-executor2:19495 blocked for more than 120 seconds. > > Not tainted 4.15.0-rc2+ #148 > > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > > syz-executor2 D25200 19495 3406 0x0004 > > Call Trace: > > context_switch kernel/sched/core.c:2799 [inline] > > __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 > > schedule+0xf5/0x430 kernel/sched/core.c:3434 > > __lock_sock+0x1dc/0x2f0 net/core/sock.c:2240 > > lock_sock_nested+0xf3/0x110 net/core/sock.c:2764 > > lock_sock include/net/sock.h:1461 [inline] > > af_alg_sendmsg+0x349/0x1080 crypto/af_alg.c:858 > > aead_sendmsg+0x103/0x150 crypto/algif_aead.c:76 > > sock_sendmsg_nosec net/socket.c:636 [inline] > > sock_sendmsg+0xca/0x110 net/socket.c:646 > > ___sys_sendmsg+0x75b/0x8a0 net/socket.c:2026 > > __sys_sendmsg+0xe5/0x210 net/socket.c:2060 > > SYSC_sendmsg net/socket.c:2071 [inline] > > SyS_sendmsg+0x2d/0x50 net/socket.c:2067 > > entry_SYSCALL_64_fastpath+0x1f/0x96 > > RIP: 0033:0x452a39 > > RSP: 002b:7f63f58cfc58 EFLAGS: 0212 ORIG_RAX: 002e > > RAX: ffda RBX: 00758020 RCX: 00452a39 > > RDX: 0040 RSI: 2063 RDI: 0015 > > RBP: 0001 R08: R09: > > R10: R11: 0212 R12: 006ee0b8 > > R13: R14: 7f63f58d06d4 R15: > > > > Showing all locks held in the system: > > 2 locks held by khungtaskd/663: > > #0: (rcu_read_lock){}, at: [ ] > > check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] > > #0: (rcu_read_lock){}, at: [ ] watchdog+0x1c5/0xd60 > > kernel/hung_task.c:249 > > #1: (tasklist_lock){.+.+}, at: [ ] > > debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 > > 1 lock held by rsyslogd/3008: > > #0: (>f_pos_lock){+.+.}, at: [ ] > > __fdget_pos+0x131/0x1a0 fs/file.c:770 > > 2 locks held by getty/3130: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3131: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3132: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3133: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3134: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3135: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3136: > > #0: (>ldisc_sem){}, at: [ ] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 1 lock held by syz-executor2/19506: > > #0: (sk_lock-AF_ALG){+.+.}, at: [ ] lock_sock > > include/net/sock.h:1461 [inline] > > #0: (sk_lock-AF_ALG){+.+.}, at: [ ] > > aead_recvmsg+0xb3/0x1bc0 crypto/algif_aead.c:327 > > I think this is a duplicate: #syz dup: INFO: task hung in aead_recvmsg There is a thread hung in aead_recvmsg() while holding the socket lock, so it's blocking other threads too. Eric
Re: INFO: task hung in lock_sock_nested
On Sun, Dec 10, 2017 at 2:37 PM, syzbotwrote: > Hello, > > syzkaller hit the following crash on > 51e18a453f5f59a40c721d4aeab082b4e2e9fac6 > git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > > Unfortunately, I don't have any reproducer for this bug yet. > > > RDS: rds_bind could not find a transport for 172.20.1.187, load rds_tcp or > rds_rdma? > INFO: task syz-executor2:19495 blocked for more than 120 seconds. > Not tainted 4.15.0-rc2+ #148 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > syz-executor2 D25200 19495 3406 0x0004 > Call Trace: > context_switch kernel/sched/core.c:2799 [inline] > __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 > schedule+0xf5/0x430 kernel/sched/core.c:3434 > __lock_sock+0x1dc/0x2f0 net/core/sock.c:2240 > lock_sock_nested+0xf3/0x110 net/core/sock.c:2764 > lock_sock include/net/sock.h:1461 [inline] > af_alg_sendmsg+0x349/0x1080 crypto/af_alg.c:858 > aead_sendmsg+0x103/0x150 crypto/algif_aead.c:76 > sock_sendmsg_nosec net/socket.c:636 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:646 > ___sys_sendmsg+0x75b/0x8a0 net/socket.c:2026 > __sys_sendmsg+0xe5/0x210 net/socket.c:2060 > SYSC_sendmsg net/socket.c:2071 [inline] > SyS_sendmsg+0x2d/0x50 net/socket.c:2067 > entry_SYSCALL_64_fastpath+0x1f/0x96 > RIP: 0033:0x452a39 > RSP: 002b:7f63f58cfc58 EFLAGS: 0212 ORIG_RAX: 002e > RAX: ffda RBX: 00758020 RCX: 00452a39 > RDX: 0040 RSI: 2063 RDI: 0015 > RBP: 0001 R08: R09: > R10: R11: 0212 R12: 006ee0b8 > R13: R14: 7f63f58d06d4 R15: > > Showing all locks held in the system: > 2 locks held by khungtaskd/663: > #0: (rcu_read_lock){}, at: [ ] > check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] > #0: (rcu_read_lock){}, at: [ ] watchdog+0x1c5/0xd60 > kernel/hung_task.c:249 > #1: (tasklist_lock){.+.+}, at: [ ] > debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 > 1 lock held by rsyslogd/3008: > #0: (>f_pos_lock){+.+.}, at: [ ] > __fdget_pos+0x131/0x1a0 fs/file.c:770 > 2 locks held by getty/3130: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3131: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3132: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3133: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3134: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3135: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 2 locks held by getty/3136: > #0: (>ldisc_sem){}, at: [ ] > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > #1: (>atomic_read_lock){+.+.}, at: [<2bd4e259>] > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > 1 lock held by syz-executor2/19506: > #0: (sk_lock-AF_ALG){+.+.}, at: [ ] lock_sock > include/net/sock.h:1461 [inline] > #0: (sk_lock-AF_ALG){+.+.}, at: [ ] > aead_recvmsg+0xb3/0x1bc0 crypto/algif_aead.c:327 > > = > > NMI backtrace for cpu 1 > CPU: 1 PID: 663 Comm: khungtaskd Not tainted 4.15.0-rc2+ #148 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 > nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 > arch_trigger_cpumask_backtrace+0x14/0x20