Re: [syzbot] [usb?] KASAN: slab-out-of-bounds Read in mon_copy_to_buff

Re: [syzbot] [usb?] KASAN: slab-out-of-bounds Read in mon_copy_to_buff

[Alan Stern]

Here's Benjamin Tissoires's patch.  Let's see if it really fixes the 
problem.

Alan Stern

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ d7b8f8e20813

The low level transport driver expects the first byte to be the report
ID, even when the report ID is not use (in which case they just shift
the buffer).

However, __hid_request() whas not offsetting the buffer it used by one
in this case, meaning that the raw_request() callback emitted by the
transport driver would be stripped of the first byte.

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Closes: https://lore.kernel.org/linux-input/c75433e0-9b47-4072-bbe8-b1d14ea97b13@rowland.harvard.edu/
Reported-by: syzbot+8258d5439c49d4c35f43@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8258d5439c49d4c35f43
Fixes: 4fa5a7f76cc7 ("HID: core: implement generic .request()")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 drivers/hid/hid-core.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 1a231dd9e4bc83202f2cbcd8b3a21e8c82b9deec..320887c365f7a36f7376556ffd19f99e52b7d732 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1976,7 +1976,7 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
 int __hid_request(struct hid_device *hid, struct hid_report *report,
 		enum hid_class_request reqtype)
 {
-	char *buf;
+	char *buf, *data_buf;
 	int ret;
 	u32 len;
 
@@ -1984,10 +1984,17 @@ int __hid_request(struct hid_device *hid, struct hid_report *report,
 	if (!buf)
 		return -ENOMEM;
 
+	data_buf = buf;
 	len = hid_report_len(report);
 
+	if (report->id == 0) {
+		/* reserve the first byte for the report ID */
+		data_buf++;
+		len++;
+	}
+
 	if (reqtype == HID_REQ_SET_REPORT)
-		hid_output_report(report, buf);
+		hid_output_report(report, data_buf);
 
 	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
 					  report->type, reqtype);

-- 
2.49.0

Re: [syzbot] [usb?] KASAN: slab-out-of-bounds Read in mon_copy_to_buff

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+8258d5439c49d4c35f43@syzkaller.appspotmail.com
Tested-by: syzbot+8258d5439c49d4c35f43@syzkaller.appspotmail.com

Tested on:

commit:         d7b8f8e2 Linux 6.16-rc5
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
console output: https://syzkaller.appspot.com/x/log.txt?x=1155ebd4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f51185bd4f40ad44
dashboard link: https://syzkaller.appspot.com/bug?extid=8258d5439c49d4c35f43
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1113ff70580000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [usb?] KASAN: slab-out-of-bounds Read in mon_copy_to_buff

[Alan Stern]

Test patch to see the contents of the report descriptor.

Alan Stern

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ d7b8f8e20813

Index: usb-devel/drivers/hid/usbhid/hid-core.c
===================================================================
--- usb-devel.orig/drivers/hid/usbhid/hid-core.c
+++ usb-devel/drivers/hid/usbhid/hid-core.c
@@ -1043,6 +1043,10 @@ static int usbhid_parse(struct hid_devic
 		goto err;
 	}
 
+	dev_info(&intf->dev, "Report descriptor:\n");
+	print_hex_dump(KERN_INFO, "  * ", DUMP_PREFIX_NONE, 16, 1,
+			rdesc, rsize, false);
+
 	ret = hid_parse_report(hid, rdesc, rsize);
 	kfree(rdesc);
 	if (ret) {

Re: [syzbot] [usb?] KASAN: slab-out-of-bounds Read in mon_copy_to_buff

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in mon_copy_to_buff

  * 00 00 00 b3 81 3e 25 03 1b dd e8 40 50 3b 5d 8c
  * 3d da
microsoft 0003:045E:07DA.0001: unknown main item tag 0x0
microsoft 0003:045E:07DA.0001: ignoring exceeding usage max
==================================================================
BUG: KASAN: slab-out-of-bounds in mon_copy_to_buff+0xc2/0x170 drivers/usb/mon/mon_bin.c:252
Read of size 3904 at addr ffff88802a9b20a1 by task kworker/1:2/3087

CPU: 1 UID: 0 PID: 3087 Comm: kworker/1:2 Not tainted 6.16.0-rc5-syzkaller-dirty #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189
 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105
 mon_copy_to_buff+0xc2/0x170 drivers/usb/mon/mon_bin.c:252
 mon_bin_get_data drivers/usb/mon/mon_bin.c:420 [inline]
 mon_bin_event+0x1071/0x2050 drivers/usb/mon/mon_bin.c:606
 mon_bus_submit+0xcf/0x140 drivers/usb/mon/mon_main.c:89
 usbmon_urb_submit include/linux/usb/hcd.h:724 [inline]
 usb_hcd_submit_urb+0x12d/0x1c60 drivers/usb/core/hcd.c:1518
 usb_submit_urb+0x87c/0x1790 drivers/usb/core/urb.c:581
 usb_start_wait_urb+0x104/0x4b0 drivers/usb/core/message.c:59
 usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
 usb_control_msg+0x326/0x4a0 drivers/usb/core/message.c:154
 usbhid_set_raw_report drivers/hid/usbhid/hid-core.c:928 [inline]
 usbhid_raw_request+0x58f/0x700 drivers/hid/usbhid/hid-core.c:1303
 __hid_request+0x296/0x3c0 drivers/hid/hid-core.c:1989
 hidinput_change_resolution_multipliers drivers/hid/hid-input.c:1950 [inline]
 hidinput_connect+0x1ada/0x2bd0 drivers/hid/hid-input.c:2327
 hid_connect+0x13f3/0x1a60 drivers/hid/hid-core.c:2239
 hid_hw_start drivers/hid/hid-core.c:2354 [inline]
 hid_hw_start+0xaa/0x140 drivers/hid/hid-core.c:2345
 ms_probe+0x195/0x500 drivers/hid/hid-microsoft.c:391
 __hid_device_probe drivers/hid/hid-core.c:2724 [inline]
 hid_device_probe+0x360/0x720 drivers/hid/hid-core.c:2761
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 hid_add_device+0x373/0xa60 drivers/hid/hid-core.c:2907
 usbhid_probe+0xd38/0x13f0 drivers/hid/usbhid/hid-core.c:1439
 usb_probe_interface+0x303/0x9c0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2694
 hub_port_connect drivers/usb/core/hub.c:5566 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5866 [inline]
 hub_event+0x2eb7/0x4fa0 drivers/usb/core/hub.c:5948
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 3087:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_noprof+0x223/0x510 mm/slub.c:4340
 __hid_request+0x2c/0x3c0 drivers/hid/hid-core.c:1980
 hidinput_change_resolution_multipliers drivers/hid/hid-input.c:1950 [inline]
 hidinput_connect+0x1ada/0x2bd0 drivers/hid/hid-input.c:2327
 hid_connect+0x13f3/0x1a60 drivers/hid/hid-core.c:2239
 hid_hw_start drivers/hid/hid-core.c:2354 [inline]
 hid_hw_start+0xaa/0x140 drivers/hid/hid-core.c:2345
 ms_probe+0x195/0x500 drivers/hid/hid-microsoft.c:391
 __hid_device_probe drivers/hid/hid-core.c:2724 [inline]
 hid_device_probe+0x360/0x720 drivers/hid/hid-core.c:2761
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 hid_add_device+0x373/0xa60 drivers/hid/hid-core.c:2907
 usbhid_probe+0xd38/0x13f0 drivers/hid/usbhid/hid-core.c:1439
 usb_probe_interface+0x303/0x9c0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2694
 hub_port_connect drivers/usb/core/hub.c:5566 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5866 [inline]
 hub_event+0x2eb7/0x4fa0 drivers/usb/core/hub.c:5948
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff88802a9b20a0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 1 bytes inside of
 allocated 7-byte region [ffff88802a9b20a0, ffff88802a9b20a7)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a9b2
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b841500 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080800080 00000000f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 10064691813, free_ts 9935982490
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab mm/slub.c:2619 [inline]
 new_slab+0x23b/0x330 mm/slub.c:2673
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 usb_get_bos_descriptor+0x62/0xbb0 drivers/usb/core/config.c:1037
 register_root_hub+0x332/0x730 drivers/usb/core/hcd.c:983
 usb_add_hcd+0xaf2/0x1730 drivers/usb/core/hcd.c:2976
 vhci_hcd_probe+0x1c2/0x490 drivers/usb/usbip/vhci_hcd.c:1377
 platform_probe+0x102/0x1f0 drivers/base/platform.c:1404
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
page last free pid 1206 tgid 1206 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
 vfree+0x1fd/0xb50 mm/vmalloc.c:3426
 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3345
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88802a9b1f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802a9b2000: 00 fc fc fc 00 fc fc fc 00 fc fc fc 00 fc fc fc
>ffff88802a9b2080: 00 fc fc fc 07 fc fc fc 06 fc fc fc 00 fc fc fc
                               ^
 ffff88802a9b2100: fa fc fc fc 00 fc fc fc 06 fc fc fc 06 fc fc fc
 ffff88802a9b2180: 06 fc fc fc 00 fc fc fc 00 fc fc fc 00 fc fc fc
==================================================================


Tested on:

commit:         d7b8f8e2 Linux 6.16-rc5
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
console output: https://syzkaller.appspot.com/x/log.txt?x=10bd1a8c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f51185bd4f40ad44
dashboard link: https://syzkaller.appspot.com/bug?extid=8258d5439c49d4c35f43
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=135800f0580000