From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> stable inclusion from stable-v6.6.136 commit 932ae5309e53561197aa7d1606c7cf63af10e24f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14366 CVE: CVE-2026-31624 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 69c02ffde6ed4d535fa4e693a9e572729cad3d0d upstream. s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does. Cc: stable <stable@kernel.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <bentiss@kernel.org> Cc: linux-input@vger.kernel.org Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Kosina <jkosina@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Xia Fukun <xiafukun@huawei.com> --- drivers/hid/hid-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index d8fda282d049..e3d728d67b53 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1356,6 +1356,9 @@ static u32 s32ton(__s32 value, unsigned n) if (!value || !n) return 0; + if (n > 32) + n = 32; + a = value >> (n - 1); if (a && a != -1) return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1; -- 2.34.1