=============================
WARNING: suspicious RCU usage
4.17.0-rc2+ #22 Not tainted
-----------------------------
include/linux/rcupdate.h:304 Illegal context switch in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
5 locks held by syz-executor1/4574:
 #0:         (ptrval) (sb_writers#4){.+.+}, at: sb_start_write include/linux/fs.h:1550 [inline]
 #0:         (ptrval) (sb_writers#4){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386
 #1:         (ptrval) (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:748 [inline]
 #1:         (ptrval) (&type->i_mutex_dir_key/1){+.+.}, at: do_unlinkat+0x3c4/0xa10 fs/namei.c:4019
 #2:         (ptrval) (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_lock include/linux/fs.h:713 [inline]
 #2:         (ptrval) (&sb->s_type->i_mutex_key#10){+.+.}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3961
 #3:         (ptrval) (jbd2_handle){.+.+}, at: start_this_handle+0x581/0x1250 fs/jbd2/transaction.c:385
 #4:         (ptrval) (rcu_read_lock){....}, at: __list_add include/linux/list.h:64 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: list_add include/linux/list.h:79 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: jbd2_write_access_granted.part.8+0x0/0x420 fs/jbd2/transaction.c:2544

stack backtrace:
CPU: 0 PID: 4574 Comm: syz-executor1 Not tainted 4.17.0-rc2+ #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4592
 rcu_preempt_sleep_check include/linux/rcupdate.h:303 [inline]
 ___might_sleep+0x26d/0x320 kernel/sched/core.c:6153
 __might_sleep+0x95/0x190 kernel/sched/core.c:6141
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3378 [inline]
 __do_kmalloc mm/slab.c:3716 [inline]
 __kmalloc+0x2b9/0x760 mm/slab.c:3727
 kmalloc_array include/linux/slab.h:631 [inline]
 kcalloc include/linux/slab.h:642 [inline]
 numa_crng_init drivers/char/random.c:798 [inline]
 crng_reseed+0x427/0x920 drivers/char/random.c:923
 credit_entropy_bits+0x98d/0xa30 drivers/char/random.c:708
 add_interrupt_randomness+0x494/0x860 drivers/char/random.c:1254
 handle_irq_event_percpu+0xf9/0x1c0 kernel/irq/handle.c:191
 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
 handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
 do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:642
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:write_comp_data+0x22/0x70 kernel/kcov.c:122
RSP: 0018:ffff88019fae7860 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd9
RAX: 0000000000000000 RBX: 1ffff10033f5cf12 RCX: ffffffff8218ab29
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff88019fae7860 R08: ffff88019fade640 R09: ffffed003b5c46c2
R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: ffff88019b172d20
R13: ffff88019fae78f0 R14: 0000000000000000 R15: 0000000000000001
 __sanitizer_cov_trace_const_cmp8+0x18/0x20 kernel/kcov.c:195
 jbd2_write_access_granted.part.8+0x109/0x420 fs/jbd2/transaction.c:1040
 jbd2_write_access_granted fs/jbd2/transaction.c:1096 [inline]
 jbd2_journal_get_write_access+0x91/0xc0 fs/jbd2/transaction.c:1086
 __ext4_journal_get_write_access+0x5e/0xa0 fs/ext4/ext4_jbd2.c:169
 ext4_delete_entry+0x2af/0x550 fs/ext4/namei.c:2356
 ext4_unlink+0x620/0x11e0 fs/ext4/namei.c:3033
 vfs_unlink+0x2db/0x510 fs/namei.c:3970
 do_unlinkat+0x6b8/0xa10 fs/namei.c:4033
 __do_sys_unlink fs/namei.c:4080 [inline]
 __se_sys_unlink fs/namei.c:4078 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4078
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4556c7
RSP: 002b:00007ffc1e5fbb28 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004556c7
RDX: 00000000024659d3 RSI: 00007ffc1e5fbbc0 RDI: 00007ffc1e5fbbc0
RBP: 00007ffc1e5fd8d0 R08: 0000000000000000 R09: 000000000000000c
R10: 0000000000000006 R11: 0000000000000206 R12: 0000000002465940
R13: 0000000000000000 R14: 00000000000001e6 R15: 0000000000022623
BUG: sleeping function called from invalid context at mm/slab.h:421
in_atomic(): 1, irqs_disabled(): 1, pid: 4574, name: syz-executor1
5 locks held by syz-executor1/4574:
 #0:         (ptrval) (sb_writers#4){.+.+}, at: sb_start_write include/linux/fs.h:1550 [inline]
 #0:         (ptrval) (sb_writers#4){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386
 #1:         (ptrval) (&type->i_mutex_dir_key/1){+.+.}, at: inode_lock_nested include/linux/fs.h:748 [inline]
 #1:         (ptrval) (&type->i_mutex_dir_key/1){+.+.}, at: do_unlinkat+0x3c4/0xa10 fs/namei.c:4019
 #2:         (ptrval) (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_lock include/linux/fs.h:713 [inline]
 #2:         (ptrval) (&sb->s_type->i_mutex_key#10){+.+.}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3961
 #3:         (ptrval) (jbd2_handle){.+.+}, at: start_this_handle+0x581/0x1250 fs/jbd2/transaction.c:385
 #4:         (ptrval) (rcu_read_lock){....}, at: __list_add include/linux/list.h:64 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: list_add include/linux/list.h:79 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: jbd2_write_access_granted.part.8+0x0/0x420 fs/jbd2/transaction.c:2544
irq event stamp: 887908
hardirqs last  enabled at (887907): [<ffffffff81b5515f>] slab_alloc mm/slab.c:3385 [inline]
hardirqs last  enabled at (887907): [<ffffffff81b5515f>] kmem_cache_alloc+0x26f/0x760 mm/slab.c:3552
hardirqs last disabled at (887908): [<ffffffff87800905>] interrupt_entry+0xb5/0xf0 arch/x86/entry/entry_64.S:625
softirqs last  enabled at (887538): [<ffffffff87a00778>] __do_softirq+0x778/0xaf5 kernel/softirq.c:311
softirqs last disabled at (887523): [<ffffffff814750c1>] invoke_softirq kernel/softirq.c:365 [inline]
softirqs last disabled at (887523): [<ffffffff814750c1>] irq_exit+0x1d1/0x200 kernel/softirq.c:405
CPU: 0 PID: 4574 Comm: syz-executor1 Not tainted 4.17.0-rc2+ #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 ___might_sleep.cold.87+0x11f/0x13a kernel/sched/core.c:6188
 __might_sleep+0x95/0x190 kernel/sched/core.c:6141
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3378 [inline]
 __do_kmalloc mm/slab.c:3716 [inline]
 __kmalloc+0x2b9/0x760 mm/slab.c:3727
 kmalloc_array include/linux/slab.h:631 [inline]
 kcalloc include/linux/slab.h:642 [inline]
 numa_crng_init drivers/char/random.c:798 [inline]
 crng_reseed+0x427/0x920 drivers/char/random.c:923
 credit_entropy_bits+0x98d/0xa30 drivers/char/random.c:708
 add_interrupt_randomness+0x494/0x860 drivers/char/random.c:1254
 handle_irq_event_percpu+0xf9/0x1c0 kernel/irq/handle.c:191
 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
 handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
 do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:245
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:642
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:write_comp_data+0x22/0x70 kernel/kcov.c:122
RSP: 0018:ffff88019fae7860 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd9
RAX: 0000000000000000 RBX: 1ffff10033f5cf12 RCX: ffffffff8218ab29
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff88019fae7860 R08: ffff88019fade640 R09: ffffed003b5c46c2
R10: ffffed003b5c46c2 R11: ffff8801dae23613 R12: ffff88019b172d20
R13: ffff88019fae78f0 R14: 0000000000000000 R15: 0000000000000001
 __sanitizer_cov_trace_const_cmp8+0x18/0x20 kernel/kcov.c:195
 jbd2_write_access_granted.part.8+0x109/0x420 fs/jbd2/transaction.c:1040
 jbd2_write_access_granted fs/jbd2/transaction.c:1096 [inline]
 jbd2_journal_get_write_access+0x91/0xc0 fs/jbd2/transaction.c:1086
 __ext4_journal_get_write_access+0x5e/0xa0 fs/ext4/ext4_jbd2.c:169
 ext4_delete_entry+0x2af/0x550 fs/ext4/namei.c:2356
 ext4_unlink+0x620/0x11e0 fs/ext4/namei.c:3033
 vfs_unlink+0x2db/0x510 fs/namei.c:3970
 do_unlinkat+0x6b8/0xa10 fs/namei.c:4033
 __do_sys_unlink fs/namei.c:4080 [inline]
 __se_sys_unlink fs/namei.c:4078 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4078
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4556c7
RSP: 002b:00007ffc1e5fbb28 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004556c7
RDX: 00000000024659d3 RSI: 00007ffc1e5fbbc0 RDI: 00007ffc1e5fbbc0
RBP: 00007ffc1e5fd8d0 R08: 0000000000000000 R09: 000000000000000c
R10: 0000000000000006 R11: 0000000000000206 R12: 0000000002465940
R13: 0000000000000000 R14: 00000000000001e6 R15: 0000000000022623
random: crng init done
9pnet_virtio: no channels available for device ./file0
9pnet_virtio: no channels available for device ./file0
xprt_adjust_timeout: rq_timeout = 0!
xprt_adjust_timeout: rq_timeout = 0!
xprt_adjust_timeout: rq_timeout = 0!
xprt_adjust_timeout: rq_timeout = 0!
rpcbind: RPC call returned error 22
rpcbind: RPC call returned error 22
rpcbind: RPC call returned error 22
rpcbind: RPC call returned error 22