Hello,
syzbot found the following crash on:
HEAD commit: 05f22368 x86, kcsan: Enable KCSAN for x86
git tree: https://github.com/google/ktsan.git kcsan
console output: https://syzkaller.appspot.com/x/log.txt?x=17ade7ef600000
kernel config: https://syzkaller.appspot.com/x/.config?x=87d111955f40591f
dashboard link: https://syzkaller.appspot.com/bug?extid=08f3e9d26e5541e1ecf2
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+08f3e9d26e5541e1ecf2@xxxxxxxxxxxxxxxxxxxxxxxxx
==================================================================
BUG: KCSAN: data-race in process_srcu / synchronize_srcu
write to 0xffffffff8604e8a0 of 8 bytes by task 17 on cpu 1:
srcu_gp_end kernel/rcu/srcutree.c:533 [inline]
srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
process_srcu+0x207/0x780 kernel/rcu/srcutree.c:1237
process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
worker_thread+0xa0/0x800 kernel/workqueue.c:2415
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
read to 0xffffffff8604e8a0 of 8 bytes by task 12515 on cpu 0:
srcu_might_be_idle kernel/rcu/srcutree.c:784 [inline]
synchronize_srcu+0x107/0x214 kernel/rcu/srcutree.c:996
fsnotify_connector_destroy_workfn+0x63/0xb0 fs/notify/mark.c:164
process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
worker_thread+0xa0/0x800 kernel/workqueue.c:2415
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12515 Comm: kworker/u4:8 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: events_unbound fsnotify_connector_destroy_workfn
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 12515 Comm: kworker/u4:8 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: events_unbound fsnotify_connector_destroy_workfn
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xf5/0x159 lib/dump_stack.c:113
panic+0x210/0x640 kernel/panic.c:221
kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
__kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
__tsan_read8 kernel/kcsan/kcsan.c:36 [inline]
__tsan_read8+0x2c/0x30 kernel/kcsan/kcsan.c:36
srcu_might_be_idle kernel/rcu/srcutree.c:784 [inline]
synchronize_srcu+0x107/0x214 kernel/rcu/srcutree.c:996
fsnotify_connector_destroy_workfn+0x63/0xb0 fs/notify/mark.c:164
process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
worker_thread+0xa0/0x800 kernel/workqueue.c:2415
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
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