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From: syzbot <syzbot+3025b9294f8cb0ede850@syzkaller.appspotmail.com>
To: bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org,
	linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org,
	netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: WARNING: suspicious RCU usage in ctrl_cmd_new_lookup
Date: Thu, 25 Jun 2020 00:29:14 -0700	[thread overview]
Message-ID: <000000000000add83505a8e38c4c@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    7ae77150 Merge tag 'powerpc-5.8-1' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14a3bcf9100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d195fe572fb15312
dashboard link: https://syzkaller.appspot.com/bug?extid=3025b9294f8cb0ede850
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11802cf9100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144acc03100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3025b9294f8cb0ede850@syzkaller.appspotmail.com

=============================
WARNING: suspicious RCU usage
5.7.0-syzkaller #0 Not tainted
-----------------------------
include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by kworker/u4:0/7:
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:279 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
 #0: ffff88821b0bd138 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239
 #1: ffffc90000cdfdc0 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243

stack backtrace:
CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 radix_tree_deref_slot include/linux/radix-tree.h:176 [inline]
 radix_tree_deref_slot include/linux/radix-tree.h:174 [inline]
 ctrl_cmd_new_lookup+0x6eb/0x7e0 net/qrtr/ns.c:558
 qrtr_ns_worker+0x5a1/0x153a net/qrtr/ns.c:674
 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this bug report. See:
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             reply	other threads:[~2020-06-25  7:29 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-25  7:29 syzbot [this message]
2020-07-02  9:44 ` WARNING: suspicious RCU usage in ctrl_cmd_new_lookup syzbot
2020-10-22 12:40 ` syzbot
2020-11-11 11:49   ` Dmitry Vyukov

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