media: tvp5150: avoid going past array on v4l2_querymenu()

The parameters of v4l2_ctrl_new_std_menu_items() are tricky: instead of
the number of possible values, it requires the number of the maximum
value. In other words, the ARRAY_SIZE() value should be decremented,
otherwise it will go past the array bounds, as warned by KASAN:

[  279.839688] BUG: KASAN: global-out-of-bounds in v4l2_querymenu+0x10d/0x180 [videodev]
[  279.839709] Read of size 8 at addr ffffffffc10a4cb0 by task v4l2-compliance/16676

[  279.839736] CPU: 1 PID: 16676 Comm: v4l2-compliance Not tainted 4.18.0-rc2+ #120
[  279.839741] Hardware name:  /NUC5i7RYB, BIOS RYBDWi35.86A.0364.2017.0511.0949 05/11/2017
[  279.839743] Call Trace:
[  279.839758]  dump_stack+0x71/0xab
[  279.839807]  ? v4l2_querymenu+0x10d/0x180 [videodev]
[  279.839817]  print_address_description+0x1c9/0x270
[  279.839863]  ? v4l2_querymenu+0x10d/0x180 [videodev]
[  279.839871]  kasan_report+0x237/0x360
[  279.839918]  v4l2_querymenu+0x10d/0x180 [videodev]
[  279.839964]  __video_do_ioctl+0x2c8/0x590 [videodev]
[  279.840011]  ? copy_overflow+0x20/0x20 [videodev]
[  279.840020]  ? avc_ss_reset+0xa0/0xa0
[  279.840028]  ? check_stack_object+0x21/0x60
[  279.840036]  ? __check_object_size+0xe7/0x240
[  279.840080]  video_usercopy+0xed/0x730 [videodev]
[  279.840123]  ? copy_overflow+0x20/0x20 [videodev]
[  279.840167]  ? v4l_enumstd+0x40/0x40 [videodev]
[  279.840177]  ? __handle_mm_fault+0x9f9/0x1ba0
[  279.840186]  ? __pmd_alloc+0x2c0/0x2c0
[  279.840193]  ? __vfs_write+0xb6/0x350
[  279.840200]  ? kernel_read+0xa0/0xa0
[  279.840244]  ? video_usercopy+0x730/0x730 [videodev]
[  279.840284]  v4l2_ioctl+0xa1/0xb0 [videodev]
[  279.840295]  do_vfs_ioctl+0x117/0x8a0
[  279.840303]  ? selinux_file_ioctl+0x211/0x2f0
[  279.840313]  ? ioctl_preallocate+0x120/0x120
[  279.840319]  ? selinux_capable+0x20/0x20
[  279.840332]  ksys_ioctl+0x70/0x80
[  279.840342]  __x64_sys_ioctl+0x3d/0x50
[  279.840351]  do_syscall_64+0x6d/0x1c0
[  279.840361]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  279.840367] RIP: 0033:0x7fdfb46275d7
[  279.840369] Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48
[  279.840474] RSP: 002b:00007ffee1179038 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  279.840483] RAX: ffffffffffffffda RBX: 00007ffee1179180 RCX: 00007fdfb46275d7
[  279.840488] RDX: 00007ffee11790c0 RSI: 00000000c02c5625 RDI: 0000000000000003
[  279.840493] RBP: 0000000000000002 R08: 0000000000000020 R09: 00000000009f0902
[  279.840497] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffee117a5a0
[  279.840501] R13: 00007ffee11790c0 R14: 0000000000000002 R15: 0000000000000000

[  279.840515] The buggy address belongs to the variable:
[  279.840535]  tvp5150_test_patterns+0x10/0xffffffffffffe360 [tvp5150]

Fixes: c43875f66140 ("[media] tvp5150: replace MEDIA_ENT_F_CONN_TEST by a control")
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
index f337e523821b6360e8ed924edfbd3e5eebf270c7..57b2102586bc3f502e12f0795c4269e88d6627a4 100644 (file)
--- a/drivers/media/i2c/tvp5150.c
+++ b/drivers/media/i2c/tvp5150.c
@@ -1534,7 +1534,7 @@ static int tvp5150_probe(struct i2c_client *c,
                        27000000, 1, 27000000);
        v4l2_ctrl_new_std_menu_items(&core->hdl, &tvp5150_ctrl_ops,
                                     V4L2_CID_TEST_PATTERN,
-                                    ARRAY_SIZE(tvp5150_test_patterns),
+                                    ARRAY_SIZE(tvp5150_test_patterns) - 1,
                                     0, 0, tvp5150_test_patterns);
        sd->ctrl_handler = &core->hdl;
        if (core->hdl.error) {