[PATCH 5.4 34/92] net: sched: prevent invalid Scell_log shift count

[Greg Kroah-Hartman]

From: Randy Dunlap <rdun...@infradead.org>

[ Upstream commit bd1248f1ddbc48b0c30565fce897a3b6423313b8 ]

Check Scell_log shift size in red_check_params() and modify all callers
of red_check_params() to pass Scell_log.

This prevents a shift out-of-bounds as detected by UBSAN:
  UBSAN: shift-out-of-bounds in ./include/net/red.h:252:22
  shift exponent 72 is too large for 32-bit type 'int'

Fixes: 8afa10cbe281 ("net_sched: red: Avoid illegal values")
Signed-off-by: Randy Dunlap <rdun...@infradead.org>
Reported-by: syzbot+97c5bd9cc81eca63d...@syzkaller.appspotmail.com
Cc: Nogah Frankel <nog...@mellanox.com>
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Cc: Cong Wang <xiyou.wangc...@gmail.com>
Cc: Jiri Pirko <j...@resnulli.us>
Cc: net...@vger.kernel.org
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Jakub Kicinski <k...@kernel.org>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 include/net/red.h     |    4 +++-
 net/sched/sch_choke.c |    2 +-
 net/sched/sch_gred.c  |    2 +-
 net/sched/sch_red.c   |    2 +-
 net/sched/sch_sfq.c   |    2 +-
 5 files changed, 7 insertions(+), 5 deletions(-)

--- a/include/net/red.h
+++ b/include/net/red.h
@@ -168,12 +168,14 @@ static inline void red_set_vars(struct r
        v->qcount       = -1;
 }
 
-static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog)
+static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog, u8 
Scell_log)
 {
        if (fls(qth_min) + Wlog > 32)
                return false;
        if (fls(qth_max) + Wlog > 32)
                return false;
+       if (Scell_log >= 32)
+               return false;
        if (qth_max < qth_min)
                return false;
        return true;
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -368,7 +368,7 @@ static int choke_change(struct Qdisc *sc
 
        ctl = nla_data(tb[TCA_CHOKE_PARMS]);
 
-       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
+       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog, 
ctl->Scell_log))
                return -EINVAL;
 
        if (ctl->limit > CHOKE_MAX_QUEUE)
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -480,7 +480,7 @@ static inline int gred_change_vq(struct
        struct gred_sched *table = qdisc_priv(sch);
        struct gred_sched_data *q = table->tab[dp];
 
-       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog)) {
+       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog, 
ctl->Scell_log)) {
                NL_SET_ERR_MSG_MOD(extack, "invalid RED parameters");
                return -EINVAL;
        }
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -213,7 +213,7 @@ static int red_change(struct Qdisc *sch,
        max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0;
 
        ctl = nla_data(tb[TCA_RED_PARMS]);
-       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog))
+       if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog, 
ctl->Scell_log))
                return -EINVAL;
 
        if (ctl->limit > 0) {
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -647,7 +647,7 @@ static int sfq_change(struct Qdisc *sch,
        }
 
        if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max,
-                                       ctl_v1->Wlog))
+                                       ctl_v1->Wlog, ctl_v1->Scell_log))
                return -EINVAL;
        if (ctl_v1 && ctl_v1->qth_min) {
                p = kmalloc(sizeof(*p), GFP_KERNEL);