Hello,
syzbot found the following crash on:
HEAD commit: 68d7a45e Linux 4.14.113
git tree: linux-4.14.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=1324bff8a00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=dbf1fde4d7489e1c
dashboard link:
https://syzkaller.appspot.com/bug?extid=709a4d3702c6f4b2e10e
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=170fb077200000
C reproducer:
https://syzkaller.appspot.com/x/repro.c?x=1379c218a00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+709a4d...@syzkaller.appspotmail.com
random: sshd: uninitialized urandom read (32 bytes read)
audit: type=1400 audit(1555876647.059:36): avc: denied { map } for
pid=7038 comm="syz-executor830" path="/root/syz-executor830216529"
dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
INFO: task syz-executor830:7059 blocked for more than 140 seconds.
Not tainted 4.14.113 #3
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor830 D28528 7059 7038 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2807 [inline]
__schedule+0x7be/0x1cf0 kernel/sched/core.c:3383
schedule+0x92/0x1c0 kernel/sched/core.c:3427
schedule_timeout+0x93d/0xe10 kernel/time/timer.c:1721
do_wait_for_common kernel/sched/completion.c:91 [inline]
__wait_for_common kernel/sched/completion.c:112 [inline]
wait_for_common kernel/sched/completion.c:123 [inline]
wait_for_completion+0x27c/0x420 kernel/sched/completion.c:144
af_alg_wait_for_completion crypto/af_alg.c:493 [inline]
af_alg_wait_for_completion+0x38/0xb0 crypto/af_alg.c:488
_aead_recvmsg crypto/algif_aead.c:314 [inline]
aead_recvmsg+0x83a/0x1da0 crypto/algif_aead.c:335
sock_recvmsg_nosec net/socket.c:819 [inline]
sock_recvmsg net/socket.c:826 [inline]
sock_recvmsg+0xc8/0x110 net/socket.c:822
sock_read_iter+0x22f/0x340 net/socket.c:903
call_read_iter include/linux/fs.h:1768 [inline]
do_iter_readv_writev+0x4f7/0x680 fs/read_write.c:672
do_iter_read+0x221/0x5b0 fs/read_write.c:916
vfs_readv+0xd3/0x130 fs/read_write.c:980
do_readv+0xc2/0x220 fs/read_write.c:1013
SYSC_readv fs/read_write.c:1100 [inline]
SyS_readv+0x28/0x30 fs/read_write.c:1097
do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x441349
RSP: 002b:00007fff2352d3c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 00000000004a23d8 RCX: 0000000000441349
RDX: 0000000000000001 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 000000000006c788 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000402170
R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
1 lock held by khungtaskd/1007:
#0: (tasklist_lock){.+.+}, at: [<ffffffff81486f98>]
debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544
2 locks held by getty/7013:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7014:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7015:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7016:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7017:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7018:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
2 locks held by getty/7019:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff861b0323>]
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8310c666>]
n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156
1 lock held by syz-executor830/7059:
#0: (sk_lock-AF_ALG){+.+.}, at: [<ffffffff82c0d0df>] lock_sock
include/net/sock.h:1462 [inline]
#0: (sk_lock-AF_ALG){+.+.}, at: [<ffffffff82c0d0df>]
af_alg_wait_for_data+0x1df/0x480 crypto/af_alg.c:800
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1007 Comm: khungtaskd Not tainted 4.14.113 #3
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+0x138/0x19c lib/dump_stack.c:53
nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
watchdog+0x5e7/0xb90 kernel/hung_task.c:274
kthread+0x31c/0x430 kernel/kthread.c:232
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff861b0e02
---
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