[PATCH 6.0 082/157] HID: core: fix shift-out-of-bounds in hid_report_raw_event

Greg Kroah-Hartman
2022-12-12T13:40:46Z

From: ZhangPeng <zhangpeng362@huawei.com>

commit ec61b41918587be530398b0d1c9a0d16619397e5 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/hid/hid-core.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1315,6 +1315,9 @@ static s32 snto32(__u32 value, unsigned
if (!value || !n)
return 0;

+ if (n > 32)
+ n = 32;
+
switch (n) {
case 8: return ((__s8)value);
case 16: return ((__s16)value);