Re: [syzbot] [usb?] KASAN: stack-out-of-bounds Read in usb_check_int_endpoints

Re: [syzbot] [usb?] KASAN: stack-out-of-bounds Read in usb_check_int_endpoints

[Alan Stern]

On Sun, Jan 26, 2025 at 08:10:22PM -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    21266b8df522 Merge tag 'AT_EXECVE_CHECK-v6.14-rc1' of git:..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14bd9c24580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f9e008bfc27b14db
> dashboard link: https://syzkaller.appspot.com/bug?extid=9c9179ac46169c56c1ad
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/5249b29d55f2/disk-21266b8d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/8413507597a1/vmlinux-21266b8d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/9c84998b8cfb/bzImage-21266b8d.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+9c9179ac46169c56c1ad@syzkaller.appspotmail.com
> 
> hid-thrustmaster 0003:044F:B65D.0004: hidraw0: USB HID v0.00 Device [HID 044f:b65d] on usb-dummy_hcd.2-1/input0
> ==================================================================
> BUG: KASAN: stack-out-of-bounds in usb_check_int_endpoints+0x1fe/0x280 drivers/usb/core/usb.c:277
> Read of size 1 at addr ffffc9000213e831 by task kworker/1:1/80
> 
> CPU: 1 UID: 0 PID: 80 Comm: kworker/1:1 Not tainted 6.13.0-syzkaller-04858-g21266b8df522 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
> Workqueue: usb_hub_wq hub_event
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
>  print_address_description mm/kasan/report.c:378 [inline]
>  print_report+0x169/0x550 mm/kasan/report.c:489
>  kasan_report+0x143/0x180 mm/kasan/report.c:602
>  usb_check_int_endpoints+0x1fe/0x280 drivers/usb/core/usb.c:277
>  thrustmaster_interrupts drivers/hid/hid-thrustmaster.c:176 [inline]
>  thrustmaster_probe+0x47d/0xcb0 drivers/hid/hid-thrustmaster.c:347

Karol:

Your commit 50420d7c79c3 ("HID: hid-thrustmaster: Fix warning in 
thrustmaster_probe by adding endpoint check") does this:

+	/* Are the expected endpoints present? */
+	u8 ep_addr[1] = {b_ep};
+
+	if (!usb_check_int_endpoints(usbif, ep_addr)) {
+		hid_err(hdev, "Unexpected non-int endpoint\n");
+		return;
+	}

usb_check_int_endpoints() expects its second argument to be a 
0-terminated byte array (see the kerneldoc).  Lack of the terminating 0 
is what caused the syzbot error reported above.

Also, usb_check_int_endpoints() is meant to be used by drivers in which 
the endpoint number is a compile-time constant.  It's not appropriate 
here.  You should have written the test as:

	if (!usb_endpoint_is_int_out(&ep->desc)) {

Alternatively, you could have called usb_find_common_endpoints().

Would you like to submit a patch to fix this error?

Alan Stern

Re: [syzbot] [usb?] KASAN: stack-out-of-bounds Read in usb_check_int_endpoints

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    6d61a53dd6f5 Merge tag 'f2fs-for-6.14-rc1' of git://git.ke..
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=13786e24580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4ddc212efe12f88
dashboard link: https://syzkaller.appspot.com/bug?extid=9c9179ac46169c56c1ad
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1514cddf980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=143c85f8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/65684dc6d116/disk-6d61a53d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/aa2e2ce680d3/vmlinux-6d61a53d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ebbf8bd929a6/bzImage-6d61a53d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c9179ac46169c56c1ad@syzkaller.appspotmail.com

usb 1-1: config 0 interface 0 has no altsetting 0
usb 1-1: New USB device found, idVendor=044f, idProduct=b65d, bcdDevice= 0.00
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
hid-thrustmaster 0003:044F:B65D.0001: hidraw0: USB HID v0.00 Device [HID 044f:b65d] on usb-dummy_hcd.0-1/input0
==================================================================
BUG: KASAN: stack-out-of-bounds in usb_check_int_endpoints+0x247/0x270 drivers/usb/core/usb.c:277
Read of size 1 at addr ffffc9000009ebb9 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.13.0-syzkaller-09030-g6d61a53dd6f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 usb_check_int_endpoints+0x247/0x270 drivers/usb/core/usb.c:277
 thrustmaster_interrupts drivers/hid/hid-thrustmaster.c:176 [inline]
 thrustmaster_probe drivers/hid/hid-thrustmaster.c:347 [inline]
 thrustmaster_probe+0x499/0xe10 drivers/hid/hid-thrustmaster.c:289
 __hid_device_probe drivers/hid/hid-core.c:2713 [inline]
 hid_device_probe+0x349/0x700 drivers/hid/hid-core.c:2750
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 hid_add_device+0x374/0xa60 drivers/hid/hid-core.c:2896
 usbhid_probe+0xd32/0x1400 drivers/hid/usbhid/hid-core.c:1431
 usb_probe_interface+0x300/0x9c0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534
 device_add+0x114b/0x1a70 drivers/base/core.c:3665
 usb_new_device+0xd09/0x1a20 drivers/usb/core/hub.c:2652
 hub_port_connect drivers/usb/core/hub.c:5523 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5663 [inline]
 port_event drivers/usb/core/hub.c:5823 [inline]
 hub_event+0x2e58/0x4f40 drivers/usb/core/hub.c:5905
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to stack of task kworker/0:1/9
 and is located at offset 65 in frame:
 thrustmaster_probe+0x0/0xe10 drivers/hid/hid-thrustmaster.c:203

This frame has 2 objects:
 [48, 52) 'trans'
 [64, 65) 'ep_addr'

The buggy address belongs to the virtual mapping at
 [ffffc90000098000, ffffc900000a1000) created by:
 kernel_clone+0xfd/0x960 kernel/fork.c:2804

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1016f1
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 2, tgid 2 (kthreadd), ts 2826831682, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xe76/0x2b90 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x21c/0x2290 mm/page_alloc.c:4739
 __alloc_pages_noprof+0xb/0x1b0 mm/page_alloc.c:4773
 __alloc_pages_node_noprof include/linux/gfp.h:265 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:292 [inline]
 vm_area_alloc_pages mm/vmalloc.c:3593 [inline]
 __vmalloc_area_node mm/vmalloc.c:3669 [inline]
 __vmalloc_node_range_noprof+0x63d/0x1530 mm/vmalloc.c:3846
 alloc_thread_stack_node kernel/fork.c:314 [inline]
 dup_task_struct kernel/fork.c:1116 [inline]
 copy_process+0x2e42/0x8c60 kernel/fork.c:2222
 kernel_clone+0xfd/0x960 kernel/fork.c:2804
 kernel_thread+0xc0/0x100 kernel/fork.c:2866
 create_kthread kernel/kthread.c:487 [inline]
 kthreadd+0x4ef/0x7d0 kernel/kthread.c:847
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page_owner free stack trace missing

Memory state around the buggy address:
 ffffc9000009ea80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000009eb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
>ffffc9000009eb80: f1 f1 f1 f1 f1 04 f2 01 f3 f3 f3 00 00 00 00 00
                                        ^
 ffffc9000009ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000009ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.