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From: syzbot <syzbot+0e4ebcc970728e056324@syzkaller.appspotmail.com>
To: johan.hedberg@gmail.com, linux-bluetooth@vger.kernel.org,
	 linux-kernel@vger.kernel.org, luiz.dentz@gmail.com,
	marcel@holtmann.org,  syzkaller-bugs@googlegroups.com
Subject: [syzbot] [bluetooth?] KASAN: wild-memory-access Read in l2cap_connect_cfm
Date: Mon, 17 Mar 2025 08:57:23 -0700	[thread overview]
Message-ID: <67d84663.050a0220.2ca2c6.0020.GAE@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    78e3fd2b7e4b Merge remote-tracking branch 'will/for-next/p..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=15b05874580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ddc962951c395b1d
dashboard link: https://syzkaller.appspot.com/bug?extid=0e4ebcc970728e056324
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6f8d7598ad09/disk-78e3fd2b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/493e8429a272/vmlinux-78e3fd2b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c843736f7c02/Image-78e3fd2b.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0e4ebcc970728e056324@syzkaller.appspotmail.com

kobject: kobject_add_internal failed for hci1:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci1: failed to register connection device
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: wild-memory-access in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: wild-memory-access in l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
BUG: KASAN: wild-memory-access in l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x538/0xde4 net/bluetooth/l2cap_core.c:7245
Read of size 4 at addr deacfffffffffc8c by task kworker/u9:3/6449

CPU: 1 UID: 0 PID: 6449 Comm: kworker/u9:3 Not tainted 6.14.0-rc6-syzkaller-g78e3fd2b7e4b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci1 hci_rx_work
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 print_report+0xf8/0x550 mm/kasan/report.c:524
 kasan_report+0xd8/0x138 mm/kasan/report.c:634
 kasan_check_range+0x268/0x2a8 mm/kasan/generic.c:189
 __kasan_check_read+0x20/0x30 mm/kasan/shadow.c:31
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
 l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
 l2cap_connect_cfm+0x538/0xde4 net/bluetooth/l2cap_core.c:7245
 hci_connect_cfm+0x120/0x1d4 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xa70/0xf80 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x114/0x404 net/bluetooth/hci_event.c:5789
 hci_le_meta_evt+0x2a4/0x478 net/bluetooth/hci_event.c:7162
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0x884/0x1060 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x31c/0xb04 net/bluetooth/hci_core.c:4015
 process_one_work+0x810/0x1638 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x97c/0xeec kernel/workqueue.c:3400
 kthread+0x65c/0x7b0 kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862
==================================================================
Unable to handle kernel paging request at virtual address fbd51fffffffff91
KASAN: maybe wild-memory-access in range [0xdeacfffffffffc88-0xdeacfffffffffc8f]
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[fbd51fffffffff91] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6449 Comm: kworker/u9:3 Tainted: G    B              6.14.0-rc6-syzkaller-g78e3fd2b7e4b #0
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci1 hci_rx_work
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
pc : atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
pc : l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
pc : l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
pc : l2cap_connect_cfm+0x53c/0xde4 net/bluetooth/l2cap_core.c:7245
lr : instrument_atomic_read include/linux/instrumented.h:68 [inline]
lr : atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
lr : l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
lr : l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
lr : l2cap_connect_cfm+0x538/0xde4 net/bluetooth/l2cap_core.c:7245
sp : ffff8000a1577460
x29: ffff8000a1577500 x28: ffff0000d4756000 x27: 1fffe0001afe1a03
x26: dfff800000000000 x25: ffff0000d47564b0 x24: ffff0000d7f0d01a
x23: dead000000000100 x22: ffff0000d7f0d2c0 x21: 1fffe0001b467007
x20: ffff0000da33803d x19: deacfffffffffc8c x18: 1fffe000366f6086
x17: ffff80008fbbd000 x16: ffff80008b7cba1c x15: 0000000000000001
x14: 1ffff0001262eaf8 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000100000 x10: 00000000000596ee x9 : 0000000000000000
x8 : 1bd59fffffffff91 x7 : 1fffe000366f6087 x6 : ffff8000803d4bfc
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000802f88ec
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] (P)
 atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] (P)
 l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] (P)
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] (P)
 l2cap_connect_cfm+0x53c/0xde4 net/bluetooth/l2cap_core.c:7245 (P)
 hci_connect_cfm+0x120/0x1d4 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xa70/0xf80 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x114/0x404 net/bluetooth/hci_event.c:5789
 hci_le_meta_evt+0x2a4/0x478 net/bluetooth/hci_event.c:7162
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0x884/0x1060 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x31c/0xb04 net/bluetooth/hci_core.c:4015
 process_one_work+0x810/0x1638 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x97c/0xeec kernel/workqueue.c:3400
 kthread+0x65c/0x7b0 kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862
Code: 52800081 aa1303e0 97568921 d343fe68 (38fa6908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	52800081 	mov	w1, #0x4                   	// #4
   4:	aa1303e0 	mov	x0, x19
   8:	97568921 	bl	0xfffffffffd5a248c
   c:	d343fe68 	lsr	x8, x19, #3
* 10:	38fa6908 	ldrsb	w8, [x8, x26] <-- trapping instruction


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             reply	other threads:[~2025-03-17 15:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-17 15:57 syzbot [this message]
2025-09-12 15:46 ` [syzbot] [bluetooth?] KASAN: wild-memory-access Read in l2cap_connect_cfm syzbot
2025-09-13  4:02   ` Hillf Danton
2025-09-13  4:28     ` syzbot
2025-10-12 10:02 ` syzbot

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