On Tue, Dec 12, 2017 at 05:47:34PM +0100, Dmitry Vyukov wrote: > On Sun, Dec 10, 2017 at 2:37 PM, syzbot > <bot+b09be8359497f2f986abf4f2db0e26de6ab1a00e@xxxxxxxxxxxxxxxxxxxxxxxxx> > 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 0x00000004 > > 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:00007f63f58cfc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e > > RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 > > RDX: 0000000000000040 RSI: 0000000020630000 RDI: 0000000000000015 > > RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee0b8 > > R13: 00000000ffffffff R14: 00007f63f58d06d4 R15: 0000000000000000 > > > > Showing all locks held in the system: > > 2 locks held by khungtaskd/663: > > #0: (rcu_read_lock){....}, at: [<00000000b2540f7c>] > > check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] > > #0: (rcu_read_lock){....}, at: [<00000000b2540f7c>] watchdog+0x1c5/0xd60 > > kernel/hung_task.c:249 > > #1: (tasklist_lock){.+.+}, at: [<00000000b425f323>] > > debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 > > 1 lock held by rsyslogd/3008: > > #0: (&f->f_pos_lock){+.+.}, at: [<00000000d620dede>] > > __fdget_pos+0x131/0x1a0 fs/file.c:770 > > 2 locks held by getty/3130: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3131: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3132: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3133: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3134: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3135: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 2 locks held by getty/3136: > > #0: (&tty->ldisc_sem){++++}, at: [<00000000ed362dba>] > > ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 > > #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002bd4e259>] > > n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 > > 1 lock held by syz-executor2/19506: > > #0: (sk_lock-AF_ALG){+.+.}, at: [<00000000bb9361fc>] lock_sock > > include/net/sock.h:1461 [inline] > > #0: (sk_lock-AF_ALG){+.+.}, at: [<00000000bb9361fc>] > > 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