Subject: [syzbot] [bridge?] [coreteam?] KASAN: vmalloc-out-of-bounds Read in __ebt_unregister_table

From: syzbot <[email-masked]>
Date: Fri, 17 Feb 2023 09:35:49 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    3ac88fa4605e Merge tag 'net-6.2-final' of git://git.kernel..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12986e58c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fe56f7d193926860
dashboard link: https://syzkaller.appspot.com/bug?extid=f61594de72d6705aea03
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14123acf480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=143058d7480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/37b6278f1cdc/disk-3ac88fa4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0a0d5eb58ca1/vmlinux-3ac88fa4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6c92dbf4b7ab/bzImage-3ac88fa4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74

CPU: 0 PID: 74 Comm: kworker/u4:4 Not tainted 6.2.0-rc8-syzkaller-00083-g3ac88fa4605e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:306 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:417
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
 __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
 ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372
 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Memory state around the buggy address:
 ffffc90005424f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005424f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90005425000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc90005425080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005425100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

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