From: Qasim Ijaz <qasdev00@gmail.com> stable inclusion from stable-v6.6.104 commit d4e6e2680807671e1c73cd6a986b33659ce92f2b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICXO12 CVE: CVE-2025-39806 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 0379eb8691b9c4477da0277ae0832036ca4410b4 upstream. A malicious HID device can trigger a slab out-of-bounds during mt_report_fixup() by passing in report descriptor smaller than 607 bytes. mt_report_fixup() attempts to patch byte offset 607 of the descriptor with 0x25 by first checking if byte offset 607 is 0x15 however it lacks bounds checks to verify if the descriptor is big enough before conducting this check. Fix this bug by ensuring the descriptor size is at least 608 bytes before accessing it. Below is the KASAN splat after the out of bounds access happens: [ 13.671954] ================================================================== [ 13.672667] BUG: KASAN: slab-out-of-bounds in mt_report_fixup+0x103/0x110 [ 13.673297] Read of size 1 at addr ffff888103df39df by task kworker/0:1/10 [ 13.673297] [ 13.673297] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.15.0-00005-gec5d573d83f4-dirty #3 [ 13.673297] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/04 [ 13.673297] Call Trace: [ 13.673297] <TASK> [ 13.673297] dump_stack_lvl+0x5f/0x80 [ 13.673297] print_report+0xd1/0x660 [ 13.673297] kasan_report+0xe5/0x120 [ 13.673297] __asan_report_load1_noabort+0x18/0x20 [ 13.673297] mt_report_fixup+0x103/0x110 [ 13.673297] hid_open_report+0x1ef/0x810 [ 13.673297] mt_probe+0x422/0x960 [ 13.673297] hid_device_probe+0x2e2/0x6f0 [ 13.673297] really_probe+0x1c6/0x6b0 [ 13.673297] __driver_probe_device+0x24f/0x310 [ 13.673297] driver_probe_device+0x4e/0x220 [ 13.673297] __device_attach_driver+0x169/0x320 [ 13.673297] bus_for_each_drv+0x11d/0x1b0 [ 13.673297] __device_attach+0x1b8/0x3e0 [ 13.673297] device_initial_probe+0x12/0x20 [ 13.673297] bus_probe_device+0x13d/0x180 [ 13.673297] device_add+0xe3a/0x1670 [ 13.673297] hid_add_device+0x31d/0xa40 [...] Fixes: c8000deb6836 ("HID: multitouch: Add support for GT7868Q") Cc: stable@vger.kernel.org Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Chen Ridong <chenridong@huawei.com> --- drivers/hid/hid-multitouch.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 6386043aab0bb..08efe665ae111 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1448,6 +1448,14 @@ static __u8 *mt_report_fixup(struct hid_device *hdev, __u8 *rdesc, if (hdev->vendor == I2C_VENDOR_ID_GOODIX && (hdev->product == I2C_DEVICE_ID_GOODIX_01E8 || hdev->product == I2C_DEVICE_ID_GOODIX_01E9)) { + if (*size < 608) { + dev_info( + &hdev->dev, + "GT7868Q fixup: report descriptor is only %u bytes, skipping\n", + *size); + return rdesc; + } + if (rdesc[607] == 0x15) { rdesc[607] = 0x25; dev_info( -- 2.34.1