bisecting fixing commit since ef244c3088856cf048c77231653b4c92a7b2213c
building syzkaller on a41ca8fa8285754d8561dcc3ed54cca2da60eed7
testing commit ef244c3088856cf048c77231653b4c92a7b2213c with gcc (GCC) 8.1.0
kernel signature: aaeb542beff477bd5e2419c8121379807357f606c8b6ddd3f8010ede73eddabc
run #0: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #1: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #2: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #3: crashed: INFO: rcu detected stall in sys_open
run #4: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #5: crashed: INFO: rcu detected stall in sys_open
run #6: crashed: INFO: rcu detected stall in sys_open
run #7: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #8: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #9: crashed: INFO: rcu detected stall in ext4_file_read_iter
testing current HEAD a1b977b49b66c75e6c51a515f6700371ae720217
testing commit a1b977b49b66c75e6c51a515f6700371ae720217 with gcc (GCC) 8.1.0
kernel signature: e841dec7057ef089799425fde3d02115a74fc4fb828ea0f40318124670f1c998
run #0: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #1: crashed: INFO: rcu detected stall in sys_open
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in ext4_file_read_iter
run #5: crashed: INFO: rcu detected stall in sys_open
run #6: crashed: INFO: rcu detected stall in corrupted
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in sys_open
run #9: crashed: INFO: rcu detected stall in ext4_file_read_iter
revisions tested: 2, total time: 28m42.802749094s (build: 18m21.644380154s, test: 9m18.37490984s)
the crash still happens on HEAD
commit msg: Linux 4.19.150
crash: INFO: rcu detected stall in ext4_file_read_iter
bridge0: port 2(bridge_slave_1) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=496/1/0x4000000000000002 softirq=8548/8551 fqs=2
rcu: (t=10501 jiffies g=4693 q=181)
rcu: rcu_preempt kthread starved for 10498 jiffies! g4693 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt R running task 29208 10 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x78c/0x1c10 kernel/sched/core.c:3517
schedule+0x7f/0x1b0 kernel/sched/core.c:3561
schedule_timeout+0x3ab/0xe00 kernel/time/timer.c:1825
rcu_gp_kthread+0xce6/0x23d0 kernel/rcu/tree.c:2202
kthread+0x347/0x410 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
NMI backtrace for cpu 0
CPU: 0 PID: 7273 Comm: syz-executor.5 Not tainted 4.19.150-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x123/0x177 lib/dump_stack.c:118
nmi_cpu_backtrace.cold.4+0x3e/0x76 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0xe6/0x11a lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
print_cpu_stall kernel/rcu/tree.c:1478 [inline]
check_cpu_stall kernel/rcu/tree.c:1550 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold.81+0x5cc/0xd67 kernel/rcu/tree.c:2682
update_process_times+0x28/0x90 kernel/time/timer.c:1650
tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:168
tick_sched_timer+0x37/0xf0 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x2f7/0xab0 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x114/0x540 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:66
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffff8880970d6c38 EFLAGS: 00010246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888174623000 RCX: 0000000000000d00
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff888174623300
RBP: ffff8880970d6c58 R08: 0000000000000000 R09: ffff888174623000
R10: ffffed102e8c47ff R11: ffff888174623fff R12: 0000000000001000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000083cfd
memset include/linux/string.h:358 [inline]
zero_user_segments include/linux/highmem.h:203 [inline]
zero_user_segment include/linux/highmem.h:215 [inline]
ext4_mpage_readpages+0x7e0/0x1560 fs/ext4/readpage.c:217
ext4_readpages+0xae/0x100 fs/ext4/inode.c:3364
read_pages+0xed/0x470 mm/readahead.c:123
__do_page_cache_readahead+0x35c/0x560 mm/readahead.c:211
ra_submit mm/internal.h:66 [inline]
ondemand_readahead+0x42b/0xbc0 mm/readahead.c:493
page_cache_async_readahead+0x311/0x5e0 mm/readahead.c:575
generic_file_buffered_read mm/filemap.c:2123 [inline]
generic_file_read_iter+0x121f/0x20d0 mm/filemap.c:2385
ext4_file_read_iter+0x139/0x350 fs/ext4/file.c:78
call_read_iter include/linux/fs.h:1815 [inline]
new_sync_read fs/read_write.c:406 [inline]
__vfs_read+0x440/0x880 fs/read_write.c:418
integrity_kernel_read+0x128/0x200 security/integrity/iint.c:200
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:364 [inline]
ima_calc_file_shash security/integrity/ima/ima_crypto.c:393 [inline]
ima_calc_file_hash+0x53a/0x800 security/integrity/ima/ima_crypto.c:458
ima_collect_measurement+0x3fc/0x520 security/integrity/ima/ima_api.c:231
process_measurement+0xb0e/0x14b0 security/integrity/ima/ima_main.c:284
ima_file_check+0xc8/0x110 security/integrity/ima/ima_main.c:391
do_last fs/namei.c:3425 [inline]
path_openat+0x746/0x3c60 fs/namei.c:3537
do_filp_open+0x177/0x250 fs/namei.c:3567
do_sys_open+0x1dd/0x350 fs/open.c:1085
__do_sys_open fs/open.c:1103 [inline]
__se_sys_open fs/open.c:1098 [inline]
__x64_sys_open+0x79/0xb0 fs/open.c:1098
do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459fc9
Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0d4a683c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459fc9
RDX: 0000000000000000 RSI: 0000000000141042 RDI: 0000000020000100
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0d4a6846d4
R13: 00000000004fa7ff R14: 00000000004dc210 R15: 00000000ffffffff