6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wang Liang <wangliang74@xxxxxxxxxx>
[ Upstream commit 9ab5cf19fb0e4680f95e506d6c544259bf1111c4 ]
Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow
in sk_dst_gso_max_size(), which may trigger a BUG_ON crash,
because sk->sk_gso_max_size would be much bigger than device limits.
Call Trace:
tcp_write_xmit
tso_segs = tcp_init_tso_segs(skb, mss_now);
tcp_set_skb_tso_segs
tcp_skb_pcount_set
// skb->len = 524288, mss_now = 8
// u16 tso_segs = 524288/8 = 65535 -> 0
tso_segs = DIV_ROUND_UP(skb->len, mss_now)
BUG_ON(!tso_segs)
Add check for the minimum value of gso_max_size and gso_ipv4_max_size.
Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation")
Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device")
Signed-off-by: Wang Liang <wangliang74@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://patch.msgid.link/20241023035213.517386-1-wangliang74@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/core/rtnetlink.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index c76c54879fddd..4acde7067519e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1984,7 +1984,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
[IFLA_NUM_TX_QUEUES] = { .type = NLA_U32 },
[IFLA_NUM_RX_QUEUES] = { .type = NLA_U32 },
[IFLA_GSO_MAX_SEGS] = { .type = NLA_U32 },
- [IFLA_GSO_MAX_SIZE] = { .type = NLA_U32 },
+ [IFLA_GSO_MAX_SIZE] = NLA_POLICY_MIN(NLA_U32, MAX_TCP_HEADER + 1),
[IFLA_PHYS_PORT_ID] = { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
[IFLA_CARRIER_CHANGES] = { .type = NLA_U32 }, /* ignored */
[IFLA_PHYS_SWITCH_ID] = { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
@@ -2009,7 +2009,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
[IFLA_TSO_MAX_SIZE] = { .type = NLA_REJECT },
[IFLA_TSO_MAX_SEGS] = { .type = NLA_REJECT },
[IFLA_ALLMULTI] = { .type = NLA_REJECT },
- [IFLA_GSO_IPV4_MAX_SIZE] = { .type = NLA_U32 },
+ [IFLA_GSO_IPV4_MAX_SIZE] = NLA_POLICY_MIN(NLA_U32, MAX_TCP_HEADER + 1),
[IFLA_GRO_IPV4_MAX_SIZE] = { .type = NLA_U32 },
};
--
2.43.0
