From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Andrew Duggan <aduggan@synaptics.com>,
Alexander Potapenko <glider@google.com>,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] HID: i2c-hid: fix OOB write in i2c_hid_set_or_send_report()
Date: Mon, 14 Mar 2016 15:21:04 -0700 [thread overview]
Message-ID: <20160314222104.GA20569@dtor-ws> (raw)
From: Dmitry Torokhov <dtor@chromium.org>
Even though hid_hw_* checks that passed in data_len is less than
HID_MAX_BUFFER_SIZE it is not enough, as i2c-hid does not necessarily
allocate buffers of HID_MAX_BUFFER_SIZE but rather checks all device
reports and select largest size. In-kernel users normally just send as much
data as report needs, so there is no problem, but hidraw users can do
whatever they please:
BUG: KASAN: slab-out-of-bounds in memcpy+0x34/0x54 at addr ffffffc07135ea80
Write of size 4101 by task syz-executor/8747
CPU: 2 PID: 8747 Comm: syz-executor Tainted: G BU 3.18.0 #37
Hardware name: Google Tegra210 Smaug Rev 1,3+ (DT)
Call trace:
[<ffffffc00020ebcc>] dump_backtrace+0x0/0x258 arch/arm64/kernel/traps.c:83
[<ffffffc00020ee40>] show_stack+0x1c/0x2c arch/arm64/kernel/traps.c:172
[< inline >] __dump_stack lib/dump_stack.c:15
[<ffffffc001958114>] dump_stack+0x90/0x140 lib/dump_stack.c:50
[< inline >] print_error_description mm/kasan/report.c:97
[< inline >] kasan_report_error mm/kasan/report.c:278
[<ffffffc0004597dc>] kasan_report+0x268/0x530 mm/kasan/report.c:305
[<ffffffc0004592e8>] __asan_storeN+0x20/0x150 mm/kasan/kasan.c:718
[<ffffffc0004594e0>] memcpy+0x30/0x54 mm/kasan/kasan.c:299
[<ffffffc001306354>] __i2c_hid_command+0x2b0/0x7b4 drivers/hid/i2c-hid/i2c-hid.c:178
[< inline >] i2c_hid_set_or_send_report drivers/hid/i2c-hid/i2c-hid.c:321
[<ffffffc0013079a0>] i2c_hid_output_raw_report.isra.2+0x3d4/0x4b8 drivers/hid/i2c-hid/i2c-hid.c:589
[<ffffffc001307ad8>] i2c_hid_output_report+0x54/0x68 drivers/hid/i2c-hid/i2c-hid.c:602
[< inline >] hid_hw_output_report include/linux/hid.h:1039
[<ffffffc0012cc7a0>] hidraw_send_report+0x400/0x414 drivers/hid/hidraw.c:154
[<ffffffc0012cc7f4>] hidraw_write+0x40/0x64 drivers/hid/hidraw.c:177
[<ffffffc0004681dc>] vfs_write+0x1d4/0x3cc fs/read_write.c:534
[< inline >] SYSC_pwrite64 fs/read_write.c:627
[<ffffffc000468984>] SyS_pwrite64+0xec/0x144 fs/read_write.c:614
Object at ffffffc07135ea80, in cache kmalloc-512
Object allocated with size 268 bytes.
Let's check data length against the buffer size before attempting to copy
data over.
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
---
This should probably go to stable as well, leaving it to Jiri/Benjamin
to decide.
drivers/hid/i2c-hid/i2c-hid.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index b921693..bb89749 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -283,17 +283,21 @@ static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
+ u16 size;
+ int args_len;
+ int index = 0;
+
+ i2c_hid_dbg(ihid, "%s\n", __func__);
+
+ if (data_len > ihid->bufsize)
+ return -EINVAL;
- /* hid_hw_* already checked that data_len < HID_MAX_BUFFER_SIZE */
- u16 size = 2 /* size */ +
+ size = 2 /* size */ +
(reportID ? 1 : 0) /* reportID */ +
data_len /* buf */;
- int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
+ args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
2 /* dataRegister */ +
size /* args */;
- int index = 0;
-
- i2c_hid_dbg(ihid, "%s\n", __func__);
if (!use_data && maxOutputLength == 0)
return -ENOSYS;
--
2.7.0.rc3.207.g0ac5344
--
Dmitry
next reply other threads:[~2016-03-14 22:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 22:21 Dmitry Torokhov [this message]
2016-03-15 7:59 ` [PATCH] HID: i2c-hid: fix OOB write in i2c_hid_set_or_send_report() Benjamin Tissoires
2016-03-15 13:34 ` Jiri Kosina
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