diff options
| author | Justin Iurman <justin.iurman@gmail.com> | 2026-04-04 15:41:37 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-04-08 19:08:56 -0700 |
| commit | b30b1675aa2bcf0491fd3830b051df4e08a7c8ca (patch) | |
| tree | 9964a4698417a6c276daaaed576bc91b9d6a41c0 /net | |
| parent | d65b175cfac64ee65506eea7fa573d291a9694ca (diff) | |
net: ioam6: fix OOB and missing lock
When trace->type.bit6 is set:
if (trace->type.bit6) {
...
queue = skb_get_tx_queue(dev, skb);
qdisc = rcu_dereference(queue->qdisc);
This code can lead to an out-of-bounds access of the dev->_tx[] array
when is_input is true. In such a case, the packet is on the RX path and
skb->queue_mapping contains the RX queue index of the ingress device. If
the ingress device has more RX queues than the egress device (dev) has
TX queues, skb_get_queue_mapping(skb) will exceed dev->num_tx_queues.
Add a check to avoid this situation since skb_get_tx_queue() does not
clamp the index. This issue has also revealed that per queue visibility
cannot be accurate and will be replaced later as a new feature.
While at it, add missing lock around qdisc_qstats_qlen_backlog(). The
function __ioam6_fill_trace_data() is called from both softirq and
process contexts, hence the use of spin_lock_bh() here.
Fixes: b63c5478e9cb ("ipv6: ioam: Support for Queue depth data field")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20260403214418.2233266-2-kuba@kernel.org/
Signed-off-by: Justin Iurman <justin.iurman@gmail.com>
Link: https://patch.msgid.link/20260404134137.24553-1-justin.iurman@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/ioam6.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c index 05a0b7d7e2aa..e963a71858a7 100644 --- a/net/ipv6/ioam6.c +++ b/net/ipv6/ioam6.c @@ -803,12 +803,16 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, struct Qdisc *qdisc; __u32 qlen, backlog; - if (dev->flags & IFF_LOOPBACK) { + if (dev->flags & IFF_LOOPBACK || + skb_get_queue_mapping(skb) >= dev->num_tx_queues) { *(__be32 *)data = cpu_to_be32(IOAM6_U32_UNAVAILABLE); } else { queue = skb_get_tx_queue(dev, skb); qdisc = rcu_dereference(queue->qdisc); + + spin_lock_bh(qdisc_lock(qdisc)); qdisc_qstats_qlen_backlog(qdisc, &qlen, &backlog); + spin_unlock_bh(qdisc_lock(qdisc)); *(__be32 *)data = cpu_to_be32(backlog); } |