Re: [syzbot] [input?] KASAN: null-ptr-deref Write in input_ff_create

From: syzbot
Date: Wed Dec 25 2024 - 18:51:16 EST

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in input_ff_create_memless

usb 1-1: New USB device found, idVendor=1949, idProduct=85a5, bcdDevice=a3.3a
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: config 0 descriptor??
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 5856 Comm: kworker/0:3 Not tainted 6.13.0-rc3-next-20241220-syzkaller-05236-g8155b4ef3466-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: usb_hub_wq hub_event
RIP: 0010:input_ff_create_memless+0x302/0x630 drivers/input/ff-memless.c:542
Code: f0 41 80 8e c3 00 00 00 01 49 81 c4 e0 00 00 00 4c 89 e3 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 e7 e8 92 2d 36 fa 49 8b 2c 24 <41> 80 7d 01 00 74 0a bf 08 00 00 00 e8 6d 2e 36 fa 48 89 2c 25 08
RSP: 0018:ffffc900041bebe0 EFLAGS: 00010246
RAX: ffffffff87ef7101 RBX: 1ffff1100c8b911c RCX: ffffffff87ef71e8
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88807a8330c0
RBP: ffff888012798000 R08: ffff88807a8330c7 R09: 1ffff1100f506618
R10: dffffc0000000000 R11: ffffed100f506619 R12: ffff8880645c88e0
R13: dffffc0000000000 R14: ffff88807a833000 R15: ffff88807a8330c0
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055597f0d4950 CR3: 000000002f18a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
xpad_init_ff drivers/input/joystick/xpad.c:1562 [inline]
xpad_init_input+0xcef/0x1440 drivers/input/joystick/xpad.c:1960
xpad_probe+0x1427/0x1b90 drivers/input/joystick/xpad.c:2143
usb_probe_interface+0x641/0xbb0 drivers/usb/core/driver.c:396
really_probe+0x2b9/0xad0 drivers/base/dd.c:658
__driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
driver_probe_device+0x50/0x430 drivers/base/dd.c:830
__device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459
__device_attach+0x333/0x520 drivers/base/dd.c:1030
bus_probe_device+0x189/0x260 drivers/base/bus.c:534
device_add+0x856/0xbf0 drivers/base/core.c:3665
usb_set_configuration+0x1976/0x1fb0 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0x88/0x140 drivers/usb/core/generic.c:254
usb_probe_device+0x1b8/0x380 drivers/usb/core/driver.c:291
really_probe+0x2b9/0xad0 drivers/base/dd.c:658
__driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
driver_probe_device+0x50/0x430 drivers/base/dd.c:830
__device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958
bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459
__device_attach+0x333/0x520 drivers/base/dd.c:1030
bus_probe_device+0x189/0x260 drivers/base/bus.c:534
device_add+0x856/0xbf0 drivers/base/core.c:3665
usb_new_device+0x104a/0x19a0 drivers/usb/core/hub.c:2651
hub_port_connect drivers/usb/core/hub.c:5521 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
port_event drivers/usb/core/hub.c:5821 [inline]
hub_event+0x2d6d/0x5150 drivers/usb/core/hub.c:5903
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:input_ff_create_memless+0x302/0x630 drivers/input/ff-memless.c:542
Code: f0 41 80 8e c3 00 00 00 01 49 81 c4 e0 00 00 00 4c 89 e3 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 e7 e8 92 2d 36 fa 49 8b 2c 24 <41> 80 7d 01 00 74 0a bf 08 00 00 00 e8 6d 2e 36 fa 48 89 2c 25 08
RSP: 0018:ffffc900041bebe0 EFLAGS: 00010246
RAX: ffffffff87ef7101 RBX: 1ffff1100c8b911c RCX: ffffffff87ef71e8
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88807a8330c0
RBP: ffff888012798000 R08: ffff88807a8330c7 R09: 1ffff1100f506618
R10: dffffc0000000000 R11: ffffed100f506619 R12: ffff8880645c88e0
R13: dffffc0000000000 R14: ffff88807a833000 R15: ffff88807a8330c0
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005648fbc7d2e8 CR3: 000000002f1b6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: f0 41 80 8e c3 00 00 lock orb $0x1,0xc3(%r14)
7: 00 01
9: 49 81 c4 e0 00 00 00 add $0xe0,%r12
10: 4c 89 e3 mov %r12,%rbx
13: 48 c1 eb 03 shr $0x3,%rbx
17: 42 80 3c 2b 00 cmpb $0x0,(%rbx,%r13,1)
1c: 74 08 je 0x26
1e: 4c 89 e7 mov %r12,%rdi
21: e8 92 2d 36 fa call 0xfa362db8
26: 49 8b 2c 24 mov (%r12),%rbp
* 2a: 41 80 7d 01 00 cmpb $0x0,0x1(%r13) <-- trapping instruction
2f: 74 0a je 0x3b
31: bf 08 00 00 00 mov $0x8,%edi
36: e8 6d 2e 36 fa call 0xfa362ea8
3b: 48 rex.W
3c: 89 .byte 0x89
3d: 2c 25 sub $0x25,%al
3f: 08 .byte 0x8


Tested on:

commit: 8155b4ef Add linux-next specific files for 20241220
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17251adf980000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c90bb7161a56c88
dashboard link: https://syzkaller.appspot.com/bug?extid=dd5f8d6456680e55eb0a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=172262f8580000