From: RD Babiera <rdbabiera@google.com> stable inclusion from stable-6.6.100 commit 45e9444b3b97eaf51a5024f1fea92f44f39b50c6 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICOXG8 CVE: CVE-2025-38391 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit af4db5a35a4ef7a68046883bfd12468007db38f1 upstream. A poorly implemented DisplayPort Alt Mode port partner can indicate that its pin assignment capabilities are greater than the maximum value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show will cause a BRK exception due to an out of bounds array access. Prevent for loop in pin_assignment_show from accessing invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop condition. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable <stable@kernel.org> Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Badhri Jagan Sridharan <badhri@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250618224943.3263103-2-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- drivers/usb/typec/altmodes/displayport.c | 2 +- include/linux/usb/typec_dp.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index ccff838ab89e..dd265e840d33 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -524,7 +524,7 @@ static ssize_t pin_assignment_show(struct device *dev, assignments = get_current_pin_assignments(dp); - for (i = 0; assignments; assignments >>= 1, i++) { + for (i = 0; assignments && i < DP_PIN_ASSIGN_MAX; assignments >>= 1, i++) { if (assignments & 1) { if (i == cur) len += sprintf(buf + len, "[%s] ", diff --git a/include/linux/usb/typec_dp.h b/include/linux/usb/typec_dp.h index 8d09c2f0a9b8..c3f08af20295 100644 --- a/include/linux/usb/typec_dp.h +++ b/include/linux/usb/typec_dp.h @@ -56,6 +56,7 @@ enum { DP_PIN_ASSIGN_D, DP_PIN_ASSIGN_E, DP_PIN_ASSIGN_F, /* Not supported after v1.0b */ + DP_PIN_ASSIGN_MAX, }; /* DisplayPort alt mode specific commands */ -- 2.34.1