3b654288b1
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. Cc: stable@vger.kernel.org Reported-by: Alexander Potapenko <glider@google.com> Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
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| Kconfig | ||
| Makefile | ||
| i2c-hid.c | ||