diff options
| author | Sven Eckelmann <sven@narfation.org> | 2026-05-29 22:11:09 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-04 13:38:37 +0200 |
| commit | c221df8bb87d9a9024654599a038be34854c2d90 (patch) | |
| tree | ecb3665069f523089b661e025c125162290dab08 | |
| parent | 7d79725a7073d86b9185f87718e22f3d65115801 (diff) | |
| download | linux-stable-c221df8bb87d9a9024654599a038be34854c2d90.tar.gz linux-stable-c221df8bb87d9a9024654599a038be34854c2d90.zip | |
batman-adv: tt: reject oversized local TVLV buffers
commit 1e9fab756f8395096d5bba7be0c373c4c8f5d165 upstream.
The commit 3a359bf5c61d ("batman-adv: reject oversized global TT response
buffers") added a check to ensure that a global return buffer size can be
stored in an u16. The same buffer handling also exists for the local data
buffer but was not touched.
A similar check should be also be in place for the local TVLV buffer. It
doesn't have the similar attack surface because it is only generated from
locally discovered MAC addresses but the dynamic nature could still cause
temporarily to large buffers.
Cc: stable@kernel.org
Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific")
[ Context ]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/batman-adv/translation-table.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index fa6dece492d3..fb51088494dc 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -943,12 +943,12 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, { struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_softif_vlan *vlan; + size_t change_offset; u16 num_vlan = 0; u16 vlan_entries = 0; u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; - int change_offset; spin_lock_bh(&bat_priv->softif_vlan_list_lock); hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { @@ -964,8 +964,10 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, if (*tt_len < 0) *tt_len = batadv_tt_len(total_entries); - tvlv_len = *tt_len; - tvlv_len += change_offset; + if (check_add_overflow(*tt_len, change_offset, &tvlv_len)) { + tvlv_len = 0; + goto out; + } *tt_data = kmalloc(tvlv_len, GFP_ATOMIC); if (!*tt_data) { |