Re: [syzbot] KASAN: slab-out-of-bounds Read in do_wait_for_common

From: syzbot <syzbot+cc699626e48a6ebaf295@syzkaller.appspotmail.com>
To: Larry.Finger@lwfinger.net, florian.c.schilhabel@googlemail.com,
	gregkh@linuxfoundation.org, hridayhegde1999@gmail.com,
	linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev,
	paskripkin@gmail.com, rkovhaev@gmail.com,
	straube.linux@gmail.com, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] KASAN: slab-out-of-bounds Read in do_wait_for_common
Date: Tue, 20 Jul 2021 15:10:08 -0700	[thread overview]
Message-ID: <0000000000001950a705c795515d@google.com> (raw)
In-Reply-To: <20210720221445.7d022a9e@gmail.com>

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: sleeping function called from invalid context in lock_sock_nested

BUG: sleeping function called from invalid context at net/core/sock.c:3161
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 8824, name: syz-executor.2
1 lock held by syz-executor.2/8824:
 #0: ffffffff8d89c920 (hci_sk_list.lock){++++}-{2:2}, at: hci_sock_dev_event+0x2b6/0x630 net/bluetooth/hci_sock.c:763
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 PID: 8824 Comm: syz-executor.2 Not tainted 5.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1d3/0x29f lib/dump_stack.c:105
 ___might_sleep+0x4e5/0x6b0 kernel/sched/core.c:9154
 lock_sock_nested+0x34/0x110 net/core/sock.c:3161
 lock_sock include/net/sock.h:1613 [inline]
 hci_sock_dev_event+0x30a/0x630 net/bluetooth/hci_sock.c:765
 hci_unregister_dev+0x487/0x19b0 net/bluetooth/hci_core.c:4033
 vhci_release+0x73/0xc0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x352/0x7b0 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x72b/0x2510 kernel/exit.c:825
 do_group_exit+0x168/0x2d0 kernel/exit.c:922
 __do_sys_exit_group+0x13/0x20 kernel/exit.c:933
 __se_sys_exit_group+0x10/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x37/0x40 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: Unable to access opcode bytes at RIP 0x4665af.
RSP: 002b:00007ffe15e4abc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffe15e4b388 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000025 R09: 00007ffe15e4b388
R10: 00000000ffffffff R11: 0000000000000246 R12: 00000000004bef54
R13: 0000000000000010 R14: 0000000000000000 R15: 0000000000400538

======================================================

Tested on:

commit:         8cae8cd8 seq_file: disallow extremely large seq buffer..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=161182ea300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=300aea483211c875
dashboard link: https://syzkaller.appspot.com/bug?extid=cc699626e48a6ebaf295
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13c31a5a300000