Message-ID: <682282b0.050a0220.f2294.00bc.GAE@google.com>
Date: Mon, 12 May 2025 16:22:24 -0700
From: syzbot <syzbot+dd3b9802ae13f63906d7@...kaller.appspotmail.com>
To: davem@...emloft.net, dsahern@...nel.org, edumazet@...gle.com, 
	horms@...nel.org, kuba@...nel.org, linux-kernel@...r.kernel.org, 
	netdev@...r.kernel.org, pabeni@...hat.com, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [net?] KASAN: global-out-of-bounds Read in in_dev_finish_destroy

Hello,

syzbot found the following issue on:

HEAD commit:    92a09c47464d Linux 6.15-rc5
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1238f8d4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b39cb28b0a399ed3
dashboard link: https://syzkaller.appspot.com/bug?extid=dd3b9802ae13f63906d7
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-92a09c47.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9dd31988ea97/vmlinux-92a09c47.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4b4e78abb078/bzImage-92a09c47.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dd3b9802ae13f63906d7@...kaller.appspotmail.com

==================================================================
BUG: KASAN: global-out-of-bounds in ref_tracker_free+0x562/0x830 lib/ref_tracker.c:244
Read of size 1 at addr ffffffff9af9a490 by task kworker/u32:1/13

CPU: 3 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 ref_tracker_free+0x562/0x830 lib/ref_tracker.c:244
 netdev_tracker_free include/linux/netdevice.h:4351 [inline]
 netdev_put include/linux/netdevice.h:4368 [inline]
 netdev_put include/linux/netdevice.h:4364 [inline]
 in_dev_finish_destroy+0xae/0x1d0 net/ipv4/devinet.c:258
 in_dev_put include/linux/inetdevice.h:290 [inline]
 inet_rcu_free_ifa+0x93/0xb0 net/ipv4/devinet.c:228
 rcu_do_batch kernel/rcu/tree.c:2568 [inline]
 rcu_core+0x799/0x14e0 kernel/rcu/tree.c:2824
 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_unregister_key+0xdd/0x130 kernel/locking/lockdep.c:6613
Code: 48 89 ef e8 b5 fe ff ff 48 89 ef e8 cd e5 ff ff 89 c3 e8 f6 ee ff ff 9c 58 f6 c4 02 75 52 41 f7 c4 00 02 00 00 74 01 fb 84 db <75> 1b 5b 5d 41 5c e9 58 5d 0a 00 8b 05 06 83 ed 0e 31 db 85 c0 74
RSP: 0018:ffffc90000107808 EFLAGS: 00000246
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dcd20c4 RDI: ffffffff8bf48260
RBP: ffffffff972ac028 R08: 000000000000c64e R09: ffffffff95c54c5c
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000246
R13: ffff88804eaa8000 R14: ffff88804eaa84c0 R15: 0000000000000001
 __qdisc_destroy+0x11a/0x4a0 net/sched/sch_generic.c:1080
 qdisc_put+0xab/0xe0 net/sched/sch_generic.c:1106
 dev_shutdown+0x1d0/0x430 net/sched/sch_generic.c:1494
 unregister_netdevice_many_notify+0xad1/0x26f0 net/core/dev.c:11969
 unregister_netdevice_many net/core/dev.c:12046 [inline]
 default_device_exit_batch+0x853/0xaf0 net/core/dev.c:12538
 ops_exit_list+0x128/0x180 net/core/net_namespace.c:177
 cleanup_net+0x5c1/0xb30 net/core/net_namespace.c:654
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the variable:
 binder_devices+0x10/0x40

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1af9a
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00006be688 ffffea00006be688 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff9af9a380: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff9af9a400: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
>ffffffff9af9a480: 00 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
                         ^
 ffffffff9af9a500: 00 00 f9 f9 f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9
 ffffffff9af9a580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9
==================================================================
----------------
Code disassembly (best guess):
   0:	48 89 ef             	mov    %rbp,%rdi
   3:	e8 b5 fe ff ff       	call   0xfffffebd
   8:	48 89 ef             	mov    %rbp,%rdi
   b:	e8 cd e5 ff ff       	call   0xffffe5dd
  10:	89 c3                	mov    %eax,%ebx
  12:	e8 f6 ee ff ff       	call   0xffffef0d
  17:	9c                   	pushf
  18:	58                   	pop    %rax
  19:	f6 c4 02             	test   $0x2,%ah
  1c:	75 52                	jne    0x70
  1e:	41 f7 c4 00 02 00 00 	test   $0x200,%r12d
  25:	74 01                	je     0x28
  27:	fb                   	sti
  28:	84 db                	test   %bl,%bl
* 2a:	75 1b                	jne    0x47 <-- trapping instruction
  2c:	5b                   	pop    %rbx
  2d:	5d                   	pop    %rbp
  2e:	41 5c                	pop    %r12
  30:	e9 58 5d 0a 00       	jmp    0xa5d8d
  35:	8b 05 06 83 ed 0e    	mov    0xeed8306(%rip),%eax        # 0xeed8341
  3b:	31 db                	xor    %ebx,%ebx
  3d:	85 c0                	test   %eax,%eax
  3f:	74                   	.byte 0x74


---
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