diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2024-05-27 18:39:55 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-05-28 19:46:41 -0700 |
| commit | fb66df20a7201e60f2b13d7f95d031b31a8831d3 (patch) | |
| tree | adaf982615c1efa41f6adbd2d0c633faf6283c00 /net/sched | |
| parent | e634134180885574d1fe7aa162777ba41e7fcd5b (diff) | |
net/sched: taprio: extend minimum interval restriction to entire cycle too
It is possible for syzbot to side-step the restriction imposed by the
blamed commit in the Fixes: tag, because the taprio UAPI permits a
cycle-time different from (and potentially shorter than) the sum of
entry intervals.
We need one more restriction, which is that the cycle time itself must
be larger than N * ETH_ZLEN bit times, where N is the number of schedule
entries. This restriction needs to apply regardless of whether the cycle
time came from the user or was the implicit, auto-calculated value, so
we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)"
branch. This way covers both conditions and scenarios.
Add a selftest which illustrates the issue triggered by syzbot.
Fixes: b5b73b26b3ca ("taprio: Fix allowing too small intervals")
Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_taprio.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 118915055360..937a0c513c17 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1151,11 +1151,6 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, list_for_each_entry(entry, &new->entries, list) cycle = ktime_add_ns(cycle, entry->interval); - if (!cycle) { - NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0"); - return -EINVAL; - } - if (cycle < 0 || cycle > INT_MAX) { NL_SET_ERR_MSG(extack, "'cycle_time' is too big"); return -EINVAL; @@ -1164,6 +1159,11 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb, new->cycle_time = cycle; } + if (new->cycle_time < new->num_entries * length_to_duration(q, ETH_ZLEN)) { + NL_SET_ERR_MSG(extack, "'cycle_time' is too small"); + return -EINVAL; + } + taprio_calculate_gate_durations(q, new); return 0; |