2021-08-31 10:38:00

by syzbot

[permalink] [raw]
Subject: [syzbot] KASAN: null-ptr-deref Read in phy_disconnect

Hello,

syzbot found the following issue on:

HEAD commit: 9c1587d99f93 usb: isp1760: otg control register access
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=16907291300000
kernel config: https://syzkaller.appspot.com/x/.config?x=24756feea212a6b0
dashboard link: https://syzkaller.appspot.com/bug?extid=6a916267d9bc5fa2d9a6
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166de449300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c5ddce300000

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

asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
usb 1-1: USB disconnect, device number 2
asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
general protection fault, probably for non-canonical address 0xdffffc00000000c3: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000618-0x000000000000061f]
CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ax88772_unbind+0x51/0x90 drivers/net/usb/asix_devices.c:816
usbnet_disconnect+0x103/0x270 drivers/net/usb/usbnet.c:1618
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
__device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1201
device_release_driver_internal drivers/base/dd.c:1232 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1255
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529
device_del+0x502/0xd40 drivers/base/core.c:3543
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419
usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2225
hub_port_connect drivers/usb/core/hub.c:5199 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5488 [inline]
port_event drivers/usb/core/hub.c:5634 [inline]
hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5716
process_one_work+0x98d/0x15b0 kernel/workqueue.c:2276
process_scheduled_works kernel/workqueue.c:2338 [inline]
worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424
kthread+0x3c0/0x4a0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
---[ end trace d08c08ba92f8f06f ]---
RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
7: 00
8: 55 push %rbp
9: 48 89 fd mov %rdi,%rbp
c: 53 push %rbx
d: e8 46 33 68 fe callq 0xfe683358
12: 48 8d bd 18 06 00 00 lea 0x618(%rbp),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 74 08 je 0x3a
32: 3c 03 cmp $0x3,%al
34: 0f 8e c5 00 00 00 jle 0xff
3a: 8b 9d 18 06 00 00 mov 0x618(%rbp),%ebx


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches


2021-08-31 13:54:35

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [syzbot] KASAN: null-ptr-deref Read in phy_disconnect

On Tue, 31 Aug 2021 03:36:23 -0700 syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 9c1587d99f93 usb: isp1760: otg control register access
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=16907291300000
> kernel config: https://syzkaller.appspot.com/x/.config?x=24756feea212a6b0
> dashboard link: https://syzkaller.appspot.com/bug?extid=6a916267d9bc5fa2d9a6
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166de449300000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c5ddce300000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
> usb 1-1: USB disconnect, device number 2
> asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
> general protection fault, probably for non-canonical address 0xdffffc00000000c3: 0000 [#1] SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000618-0x000000000000061f]
> CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.14.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
> RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
> Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
> RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
> RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
> RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
> RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
> R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
> R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
> FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> ax88772_unbind+0x51/0x90 drivers/net/usb/asix_devices.c:816
> usbnet_disconnect+0x103/0x270 drivers/net/usb/usbnet.c:1618
> usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458
> __device_release_driver+0x3bd/0x6f0 drivers/base/dd.c:1201
> device_release_driver_internal drivers/base/dd.c:1232 [inline]
> device_release_driver+0x26/0x40 drivers/base/dd.c:1255
> bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529
> device_del+0x502/0xd40 drivers/base/core.c:3543
> usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419
> usb_disconnect.cold+0x27a/0x78e drivers/usb/core/hub.c:2225
> hub_port_connect drivers/usb/core/hub.c:5199 [inline]
> hub_port_connect_change drivers/usb/core/hub.c:5488 [inline]
> port_event drivers/usb/core/hub.c:5634 [inline]
> hub_event+0x1c9c/0x4330 drivers/usb/core/hub.c:5716
> process_one_work+0x98d/0x15b0 kernel/workqueue.c:2276
> process_scheduled_works kernel/workqueue.c:2338 [inline]
> worker_thread+0x85c/0x11f0 kernel/workqueue.c:2424
> kthread+0x3c0/0x4a0 kernel/kthread.c:319
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
> Modules linked in:
> ---[ end trace d08c08ba92f8f06f ]---
> RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
> RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
> Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
> RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
> RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
> RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
> RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
> R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
> R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
> FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
> 7: 00
> 8: 55 push %rbp
> 9: 48 89 fd mov %rdi,%rbp
> c: 53 push %rbx
> d: e8 46 33 68 fe callq 0xfe683358
> 12: 48 8d bd 18 06 00 00 lea 0x618(%rbp),%rdi
> 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
> 20: fc ff df
> 23: 48 89 fa mov %rdi,%rdx
> 26: 48 c1 ea 03 shr $0x3,%rdx
> * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
> 2e: 84 c0 test %al,%al
> 30: 74 08 je 0x3a
> 32: 3c 03 cmp $0x3,%al
> 34: 0f 8e c5 00 00 00 jle 0xff
> 3a: 8b 9d 18 06 00 00 mov 0x618(%rbp),%ebx
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at [email protected].
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches

Oleksij may know.

2021-08-31 14:24:52

by Andrew Lunn

[permalink] [raw]
Subject: Re: [syzbot] KASAN: null-ptr-deref Read in phy_disconnect

On Tue, Aug 31, 2021 at 06:48:45AM -0700, Jakub Kicinski wrote:
> On Tue, 31 Aug 2021 03:36:23 -0700 syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 9c1587d99f93 usb: isp1760: otg control register access
> > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16907291300000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=24756feea212a6b0
> > dashboard link: https://syzkaller.appspot.com/bug?extid=6a916267d9bc5fa2d9a6
> > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166de449300000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c5ddce300000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: [email protected]
> >
> > asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
> > usb 1-1: USB disconnect, device number 2
> > asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
> > general protection fault, probably for non-canonical address 0xdffffc00000000c3: 0000 [#1] SMP KASAN
> > KASAN: null-ptr-deref in range [0x0000000000000618-0x000000000000061f]
> > CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.14.0-rc7-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Workqueue: usb_hub_wq hub_event
> > RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
> > RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
> > Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
> > RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
> > RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
> > RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
> > RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
> > R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
> > R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
> > FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > ax88772_unbind+0x51/0x90 drivers/net/usb/asix_devices.c:816

Looking at the console messages:

[ 36.456221][ T32] usb 1-1: new high-speed USB device number 2 using dummy_hcd
[ 36.976035][ T32] usb 1-1: New USB device found, idVendor=0df6, idProduct=0056, bcdDevice=42.6c
[ 36.985338][ T32] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 36.993579][ T32] usb 1-1: Product: syz
[ 36.997817][ T32] usb 1-1: Manufacturer: syz
[ 37.002423][ T32] usb 1-1: SerialNumber: syz
[ 37.013578][ T32] usb 1-1: config 0 descriptor??
[ 37.276018][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): invalid hw address, using random
executing program
[ 37.715517][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
[ 37.725693][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
[ 37.925418][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
[ 37.936461][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
[ 38.119561][ T32] asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
[ 38.138828][ T32] usb 1-1: USB disconnect, device number 2
[ 38.150689][ T32] asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet

So this is a AX88178, and you would expect it to use
ax88178_bind(). That function never calls ax88772_init_phy() which is
what connects the PHY to the MAC, and sets priv->phydev.

static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
{
struct asix_common_private *priv = dev->driver_priv;

phy_disconnect(priv->phydev);

So this passes a NULL pointer.

static const struct driver_info ax88178_info = {
.description = "ASIX AX88178 USB 2.0 Ethernet",
.bind = ax88178_bind,
.unbind = ax88772_unbind,
.status = asix_status,

You cannot pair ax88178_bind with ax88772_unbind. Either a
ax88178_unbind is needed, or ax88772_unbind needs to check for a NULL
pointer.

Andrew

2021-08-31 15:37:12

by Oleksij Rempel

[permalink] [raw]
Subject: Re: [syzbot] KASAN: null-ptr-deref Read in phy_disconnect

Am 31.08.21 um 16:20 schrieb Andrew Lunn:
> On Tue, Aug 31, 2021 at 06:48:45AM -0700, Jakub Kicinski wrote:
>> On Tue, 31 Aug 2021 03:36:23 -0700 syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following issue on:
>>>
>>> HEAD commit: 9c1587d99f93 usb: isp1760: otg control register access
>>> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=16907291300000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=24756feea212a6b0
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=6a916267d9bc5fa2d9a6
>>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
>>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=166de449300000
>>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c5ddce300000
>>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: [email protected]
>>>
>>> asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
>>> usb 1-1: USB disconnect, device number 2
>>> asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
>>> general protection fault, probably for non-canonical address 0xdffffc00000000c3: 0000 [#1] SMP KASAN
>>> KASAN: null-ptr-deref in range [0x0000000000000618-0x000000000000061f]
>>> CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.14.0-rc7-syzkaller #0
>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
>>> Workqueue: usb_hub_wq hub_event
>>> RIP: 0010:phy_is_started include/linux/phy.h:947 [inline]
>>> RIP: 0010:phy_disconnect+0x22/0x110 drivers/net/phy/phy_device.c:1097
>>> Code: 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 46 33 68 fe 48 8d bd 18 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e c5 00 00 00 8b 9d 18 06 00 00
>>> RSP: 0018:ffffc900001a7780 EFLAGS: 00010206
>>> RAX: dffffc0000000000 RBX: ffff88811a410bc0 RCX: 0000000000000000
>>> RDX: 00000000000000c3 RSI: ffffffff82d9305a RDI: 0000000000000618
>>> RBP: 0000000000000000 R08: 0000000000000055 R09: 0000000000000000
>>> R10: ffffffff814c05fb R11: 0000000000000000 R12: ffff8881063cc300
>>> R13: ffffffff83870d90 R14: ffffffff86805a20 R15: ffffffff868059e0
>>> FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 00007fb4c30b3008 CR3: 00000001021e1000 CR4: 00000000001506e0
>>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>> Call Trace:
>>> ax88772_unbind+0x51/0x90 drivers/net/usb/asix_devices.c:816
>
> Looking at the console messages:
>
> [ 36.456221][ T32] usb 1-1: new high-speed USB device number 2 using dummy_hcd
> [ 36.976035][ T32] usb 1-1: New USB device found, idVendor=0df6, idProduct=0056, bcdDevice=42.6c
> [ 36.985338][ T32] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> [ 36.993579][ T32] usb 1-1: Product: syz
> [ 36.997817][ T32] usb 1-1: Manufacturer: syz
> [ 37.002423][ T32] usb 1-1: SerialNumber: syz
> [ 37.013578][ T32] usb 1-1: config 0 descriptor??
> [ 37.276018][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): invalid hw address, using random
> executing program
> [ 37.715517][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
> [ 37.725693][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
> [ 37.925418][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
> [ 37.936461][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
> [ 38.119561][ T32] asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
> [ 38.138828][ T32] usb 1-1: USB disconnect, device number 2
> [ 38.150689][ T32] asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
>
> So this is a AX88178, and you would expect it to use
> ax88178_bind(). That function never calls ax88772_init_phy() which is
> what connects the PHY to the MAC, and sets priv->phydev.
>
> static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
> {
> struct asix_common_private *priv = dev->driver_priv;
>
> phy_disconnect(priv->phydev);
>
> So this passes a NULL pointer.
>
> static const struct driver_info ax88178_info = {
> .description = "ASIX AX88178 USB 2.0 Ethernet",
> .bind = ax88178_bind,
> .unbind = ax88772_unbind,
> .status = asix_status,
>
> You cannot pair ax88178_bind with ax88772_unbind. Either a
> ax88178_unbind is needed, or ax88772_unbind needs to check for a NULL
> pointer.
>
> Andrew
>

Yes, this was fixed following patch:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/drivers/net/usb/asix_devices.c?id=1406e8cb4b05fdc67692b1af2da39d7ca5278713

--
Regards,
Oleksij

2021-08-31 15:41:10

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [syzbot] KASAN: null-ptr-deref Read in phy_disconnect

On Tue, 31 Aug 2021 17:30:19 +0200 Oleksij Rempel wrote:
> Am 31.08.21 um 16:20 schrieb Andrew Lunn:
> > On Tue, Aug 31, 2021 at 06:48:45AM -0700, Jakub Kicinski wrote:
> >> On Tue, 31 Aug 2021 03:36:23 -0700 syzbot wrote:
> [...]
> >
> > Looking at the console messages:
> >
> > [ 36.456221][ T32] usb 1-1: new high-speed USB device number 2 using dummy_hcd
> > [ 36.976035][ T32] usb 1-1: New USB device found, idVendor=0df6, idProduct=0056, bcdDevice=42.6c
> > [ 36.985338][ T32] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> > [ 36.993579][ T32] usb 1-1: Product: syz
> > [ 36.997817][ T32] usb 1-1: Manufacturer: syz
> > [ 37.002423][ T32] usb 1-1: SerialNumber: syz
> > [ 37.013578][ T32] usb 1-1: config 0 descriptor??
> > [ 37.276018][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): invalid hw address, using random
> > executing program
> > [ 37.715517][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
> > [ 37.725693][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
> > [ 37.925418][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71
> > [ 37.936461][ T32] asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to send software reset: ffffffb9
> > [ 38.119561][ T32] asix 1-1:0.0 eth1: register 'asix' at usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet, 8a:c0:d1:1e:27:4c
> > [ 38.138828][ T32] usb 1-1: USB disconnect, device number 2
> > [ 38.150689][ T32] asix 1-1:0.0 eth1: unregister 'asix' usb-dummy_hcd.0-1, ASIX AX88178 USB 2.0 Ethernet
> >
> > So this is a AX88178, and you would expect it to use
> > ax88178_bind(). That function never calls ax88772_init_phy() which is
> > what connects the PHY to the MAC, and sets priv->phydev.
> >
> > static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
> > {
> > struct asix_common_private *priv = dev->driver_priv;
> >
> > phy_disconnect(priv->phydev);
> >
> > So this passes a NULL pointer.
> >
> > static const struct driver_info ax88178_info = {
> > .description = "ASIX AX88178 USB 2.0 Ethernet",
> > .bind = ax88178_bind,
> > .unbind = ax88772_unbind,
> > .status = asix_status,
> >
> > You cannot pair ax88178_bind with ax88772_unbind. Either a
> > ax88178_unbind is needed, or ax88772_unbind needs to check for a NULL
> > pointer.
> >
> > Andrew
> >
>
> Yes, this was fixed following patch:
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/drivers/net/usb/asix_devices.c?id=1406e8cb4b05fdc67692b1af2da39d7ca5278713

#syz fix: net: usb: asix: do not call phy_disconnect() for ax88178