syzbot
WARNING: suspicious RCU usage in ctrl_cmd_new_lookup
Status:
fixed on 2020/11/16 12:12
Subsystems:
net
arm-msm
[Documentation on labels]
Reported-by: syzbot+3025b9294f8cb0ede850@syzkaller.appspotmail.com
Fix commit:
a7809ff90ce6
net: qrtr: ns: Protect radix_tree_deref_slot() using rcu read locks
First crash: 2221d, last: 2132d
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Last patch testing requests (3)
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Fix bisection attempts (3)
Sample crash report:
=============================
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
* Struck through repros no longer work on HEAD.