From ec61b41918587be530398b0d1c9a0d16619397e5 Mon Sep 17 00:00:00 2001

From: ZhangPeng <zhangpeng362@huawei.com>

Date: Wed, 16 Nov 2022 07:14:28 +0000

Subject: [PATCH] HID: core: fix shift-out-of-bounds in hid_report_raw_event

Git-commit: ec61b41918587be530398b0d1c9a0d16619397e5

Patch-mainline: v6.1

References: git-fixes

Syzbot reported shift-out-of-bounds in hid_report_raw_event.

microsoft 0003:045E:07DA.0001: hid_field_extract() called with n (128) >

32! (swapper/0)

======================================================================

Ubsan: shift-out-of-bounds in drivers/hid/hid-core.c:1323:20

shift exponent 127 is too large for 32-bit type 'int'

Cpu: 0 PID: 0 Comm: swapper/0 Not tainted

6.1.0-rc4-syzkaller-00159-g4bbf3422df78 #0

Hardware name: Google Compute Engine/Google Compute Engine, BIOS

Google 10/26/2022

Call Trace:

 <IRQ>

 __dump_stack lib/dump_stack.c:88 [inline]

 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106

 ubsan_epilogue lib/ubsan.c:151 [inline]

 __ubsan_handle_shift_out_of_bounds+0x3a6/0x420 lib/ubsan.c:322

 snto32 drivers/hid/hid-core.c:1323 [inline]

 hid_input_fetch_field drivers/hid/hid-core.c:1572 [inline]

 hid_process_report drivers/hid/hid-core.c:1665 [inline]

 hid_report_raw_event+0xd56/0x18b0 drivers/hid/hid-core.c:1998

 hid_input_report+0x408/0x4f0 drivers/hid/hid-core.c:2066

 hid_irq_in+0x459/0x690 drivers/hid/usbhid/hid-core.c:284

 __usb_hcd_giveback_urb+0x369/0x530 drivers/usb/core/hcd.c:1671

 dummy_timer+0x86b/0x3110 drivers/usb/gadget/udc/dummy_hcd.c:1988

 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474

 expire_timers kernel/time/timer.c:1519 [inline]

 __run_timers+0x76a/0x980 kernel/time/timer.c:1790

 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803

 __do_softirq+0x277/0x75b kernel/softirq.c:571

 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:650

 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662

 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1107

======================================================================

If the size of the integer (unsigned n) is bigger than 32 in snto32(),

shift exponent will be too large for 32-bit type 'int', resulting in a

shift-out-of-bounds bug.

Fix this by adding a check on the size of the integer (unsigned n) in

snto32(). To add support for n greater than 32 bits, set n to 32, if n

is greater than 32.

Reported-by: syzbot+8b1641d2f14732407e23@syzkaller.appspotmail.com

Fixes: dde5845a529f ("[PATCH] Generic HID layer - code split")

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/hid/hid-core.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c

index 9c1d31f63f85..bd47628da6be 100644

--- a/drivers/hid/hid-core.c

+++ b/drivers/hid/hid-core.c

@@ -1315,6 +1315,9 @@ static s32 snto32(__u32 value, unsigned n)

 	if (!value || !n)

 		return 0;

+	if (n > 32)

+		n = 32;

+

 	switch (n) {

 	case 8:  return ((__s8)value);

 	case 16: return ((__s16)value);

-- 

2.35.3