From: Zhengchuan Liang Date: Tue, 9 Jun 2026 08:34:37 +0000 (+0800) Subject: net: atm: reject out-of-range traffic classes in QoS validation X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cdf19f380e46192e7084be559638aab1f6ed86a2;p=thirdparty%2Flinux.git net: atm: reject out-of-range traffic classes in QoS validation Reject ATM traffic classes above ATM_ANYCLASS in check_tp(). SO_ATMQOS stores the supplied QoS after check_qos() succeeds, so accepting larger values leaves invalid traffic_class values in vcc->qos. That bad state later reaches pvc_info(), which indexes class_name[] with vcc->qos.{rx,tp}.traffic_class. Values above ATM_ANYCLASS cause an out-of-bounds read when /proc/net/atm/pvc is read. Tighten the existing QoS validation so invalid traffic_class values are rejected at the point where user supplied QoS is accepted. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Yuan Tan Reported-by: Xin Liu Signed-off-by: Zhengchuan Liang Signed-off-by: Ren Wei Reviewed-by: Simon Horman Link: https://patch.msgid.link/58f02c6f73d9818fd5d2022e1116759fdde6116b.1780965530.git.zcliangcn@gmail.com Signed-off-by: Jakub Kicinski --- diff --git a/net/atm/common.c b/net/atm/common.c index fe77f51f6ce18..6eb78c34c2843 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -720,6 +720,8 @@ static int atm_change_qos(struct atm_vcc *vcc, struct atm_qos *qos) static int check_tp(const struct atm_trafprm *tp) { /* @@@ Should be merged with adjust_tp */ + if (tp->traffic_class > ATM_ANYCLASS) + return -EINVAL; if (!tp->traffic_class || tp->traffic_class == ATM_ANYCLASS) return 0; if (tp->traffic_class != ATM_UBR && !tp->min_pcr && !tp->pcr &&