linux-kernel - Re: [syzbot] [bpf?] possible deadlock in kvfree_call

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240328230738.2910-1-hdanton@sina.com>
Date: Fri, 29 Mar 2024 07:07:38 +0800
From: Hillf Danton <hdanton@...a.com>
To: syzbot <syzbot+1fa663a2100308ab6eab@...kaller.appspotmail.com>
Cc: linux-kernel@...r.kernel.org,
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [bpf?] possible deadlock in kvfree_call_rcu

On Wed, 27 Mar 2024 16:27:19 -0700
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    443574b03387 riscv, bpf: Fix kfunc parameters incompatibil..
> git tree:       bpf
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ca53c9180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  master

--- x/kernel/rcu/tree.c
+++ y/kernel/rcu/tree.c
@@ -5149,6 +5149,8 @@ static void __init rcu_dump_rcu_node_tre
 
 struct workqueue_struct *rcu_gp_wq;
 
+static DEFINE_PER_CPU(struct lock_class_key, krc_lock_key);
+
 static void __init kfree_rcu_batch_init(void)
 {
 	int cpu;
@@ -5169,6 +5171,11 @@ static void __init kfree_rcu_batch_init(
 
 	for_each_possible_cpu(cpu) {
 		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
+		struct lock_class_key *key = per_cpu_ptr(&krc_lock_key, cpu);
+		char name[32] = {0};
+
+		sprintf(name, "krc%d", cpu);
+		lockdep_set_class_and_name(&krcp->lock, key, name);
 
 		for (i = 0; i < KFREE_N_BATCHES; i++) {
 			INIT_RCU_WORK(&krcp->krw_arr[i].rcu_work, kfree_rcu_work);
--