git: 6b597a9470ad - stable/15 - uchcom: Set rate to 1 if 0

The branch stable/15 has been updated by aokblast:

URL: https://cgit.FreeBSD.org/src/commit/?id=6b597a9470ad3d31b2014ae2380a12dda5181818

commit 6b597a9470ad3d31b2014ae2380a12dda5181818
Author:     ShengYi Hung <aokblast@FreeBSD.org>
AuthorDate: 2026-09-26 06:42:39 +0000
Commit:     ShengYi Hung <aokblast@FreeBSD.org>
CommitDate: 2026-11-01 22:07:40 +0000

    uchcom: Set rate to 1 if 0
    
    If userspace provides rate == 0, it causes kernel panic as rate is
    directly used as a divident, which cannot be zero. Fix it by set the
    rate to 1 if it is passed as 0.
    
    Reviewed by:    imp, emaste
    MFC after:      2 weeks
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D59111
    
    (cherry picked from commit 228b1a011660ee1005bc4ab7c97113af8d87fe5c)
---
 sys/dev/usb/serial/uchcom.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/dev/usb/serial/uchcom.c b/sys/dev/usb/serial/uchcom.c
index ff1ac8897c90..d315b2d37c46 100644
--- a/sys/dev/usb/serial/uchcom.c
+++ b/sys/dev/usb/serial/uchcom.c
@@ -628,6 +628,9 @@ uchcom_calc_baudrate(struct uchcom_softc *sc, uint32_t rate, uint8_t *divisor,
 		*divisor = 0;
 	}
 
+	if (rate == 0)
+		rate = 1;
+
 	*factor = 256 - clk / rate;
 
 	if (rate == 921600 && sc->sc_chiptype != TYPE_CH343) {