samsung_sm8750/android_kernel_samsung_sm8750
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net_sched: sch_sfq: reject invalid perturb period

Browse Source 
commit 7ca52541c05c832d32b112274f81a985101f9ba8 upstream.

Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.

We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.

Tested:

tc qd add dev lo root sfq perturb -10   # negative value : error
Error: sch_sfq: invalid perturb period.

tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.

tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
 Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
 backlog 0b 0p requeues 0

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Dumazet
2025-06-11 08:35:01 +00:00
committed by Greg Kroah-Hartman
parent bb9d4ffff6
commit 0357da9149
1 changed files with 8 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
net/sched/sch_sfq.c
View File

@@ -656,6 +656,14 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
NL_SET_ERR_MSG_MOD(extack, "invalid quantum");
return -EINVAL;
}
if (ctl->perturb_period < 0 ||
ctl->perturb_period > INT_MAX / HZ) {
NL_SET_ERR_MSG_MOD(extack, "invalid perturb period");
return -EINVAL;
}
perturb_period = ctl->perturb_period * HZ;
if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max,
ctl_v1->Wlog, ctl_v1->Scell_log, NULL))
return -EINVAL;
@@ -672,14 +680,12 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt,
headdrop = q->headdrop;
maxdepth = q->maxdepth;
maxflows = q->maxflows;
perturb_period = q->perturb_period;
quantum = q->quantum;
flags = q->flags;
/* update and validate configuration */
if (ctl->quantum)
quantum = ctl->quantum;
perturb_period = ctl->perturb_period * HZ;
if (ctl->flows)
maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS);
if (ctl->divisor) {