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| author | Sven Eckelmann <sven@narfation.org> | 2026-05-29 23:36:43 +0200 |
|---|---|---|
| committer | Sven Eckelmann <sven@narfation.org> | 2026-06-03 08:27:16 +0200 |
| commit | 5e50d4b8ae3ea622122d3c6a38d7f6fe68dfddca (patch) | |
| tree | 0eb1ebe51370f9526e322ac133af4fe84f3dab35 | |
| parent | 98b0fb191c878a64cbaebfe231d96d57576acf8c (diff) | |
| download | linux-5e50d4b8ae3ea622122d3c6a38d7f6fe68dfddca.tar.gz linux-5e50d4b8ae3ea622122d3c6a38d7f6fe68dfddca.zip | |
batman-adv: prevent ELP transmission interval underflow
batadv_v_elp_start_timer() enqeues a delayed work. The time when it starts
is randomly chosen between (elp_interval - BATADV_JITTER) and
(elp_interval + BATADV_JITTER). The configured elp_interval must therefore
be larger or equal to BATADV_JITTER to avoid that it causes an underflow of
the unsigned integer. If this would happen, then a "fast" ELP interval
would turn into a "day long" delay.
At the same time, it must not be larger than the maximum value the variable
can store.
Cc: stable@kernel.org
Fixes: a10800829040 ("batman-adv: Add elp_interval hardif genl configuration")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
| -rw-r--r-- | net/batman-adv/netlink.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c index e5463003a3bd..1ba206e40273 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -919,9 +919,15 @@ static int batadv_netlink_set_hardif(struct sk_buff *skb, #ifdef CONFIG_BATMAN_ADV_BATMAN_V if (info->attrs[BATADV_ATTR_ELP_INTERVAL]) { + u32 elp_interval; + attr = info->attrs[BATADV_ATTR_ELP_INTERVAL]; + elp_interval = nla_get_u32(attr); + + elp_interval = min_t(u32, elp_interval, INT_MAX); + elp_interval = max_t(u32, elp_interval, BATADV_JITTER); - WRITE_ONCE(hard_iface->bat_v.elp_interval, nla_get_u32(attr)); + WRITE_ONCE(hard_iface->bat_v.elp_interval, elp_interval); } if (info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE]) { |