• ZhangPeng's avatar
    HID: core: fix shift-out-of-bounds in hid_report_raw_event · ec61b419
    ZhangPeng authored
    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-g4bbf3422 #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: dde5845a ("[PATCH] Generic HID layer - code split")
    Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
    Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
    ec61b419
hid-core.c 72.1 KB