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 @@ -1310,6 +1310,9 @@ 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);