net/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash()

Browse source

[ Upstream commit be054cc66f ]

Commit 38a6f08657 ("net: sched: support hash selecting tx queue")
added SKBEDIT_F_TXQ_SKBHASH support. The inclusive range size is
computed as:

mapping_mod = queue_mapping_max - queue_mapping + 1;

The range size can be 65536 when the requested range covers all possible
u16 queue IDs (e.g. queue_mapping=0 and queue_mapping_max=U16_MAX).
That value cannot be represented in a u16 and previously wrapped to 0,
so tcf_skbedit_hash() could trigger a divide-by-zero:

queue_mapping += skb_get_hash(skb) % params->mapping_mod;

Compute mapping_mod in a wider type and reject ranges larger than U16_MAX
to prevent params->mapping_mod from becoming 0 and avoid the crash.

Fixes: 38a6f08657 ("net: sched: support hash selecting tx queue")
Cc: stable@vger.kernel.org # 6.12+
Signed-off-by: Ruitong Liu <cnitlrt@gmail.com>
Link: https://patch.msgid.link/20260213175948.1505257-1-cnitlrt@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Ruitong Liu 2026-02-14 01:59:48 +08:00 • committed by Sasha Levin

parent 1b1371cd40

commit 015cebdfcb

1 changed files with 5 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

6

net/sched/act_skbedit.c

View file