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| author | Sven Eckelmann <sven@narfation.org> | 2026-06-26 18:11:24 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-04 13:42:24 +0200 |
| commit | b88f8f4e5e78e4e236e125399a17de29983d348e (patch) | |
| tree | 5d8da4605a1bd7ec96263dfeab681a3481e5ffbe | |
| parent | b5cf66cdc49b13169e4241c9671633fcb99a1101 (diff) | |
| download | linux-b88f8f4e5e78e4e236e125399a17de29983d348e.tar.gz linux-b88f8f4e5e78e4e236e125399a17de29983d348e.zip | |
batman-adv: prevent ELP transmission interval underflow
commit 5e50d4b8ae3ea622122d3c6a38d7f6fe68dfddca upstream.
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")
[ Context ]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Sasha Levin <sashal@kernel.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 0c64d81a7761..03ba6282af91 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -938,9 +938,15 @@ 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); - atomic_set(&hard_iface->bat_v.elp_interval, nla_get_u32(attr)); + atomic_set(&hard_iface->bat_v.elp_interval, elp_interval); } if (info->attrs[BATADV_ATTR_THROUGHPUT_OVERRIDE]) { |