Re: [PATCH 5.15.y 4/6] net: fix crash when config small gso_max_size/gso_ipv4_max_size

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 9ab5cf19fb0e4680f95e506d6c544259bf1111c4

WARNING: Author mismatch between patch and upstream commit:
Backport author: Harshit Mogalapalli<harshit.m.mogalapalli@oracle.com>
Commit author: Wang Liang<wangliang74@huawei.com>

Status in newer kernel trees:
6.14.y | Present (exact SHA1)
6.13.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: ac5977001eee)
6.1.y | Present (different SHA1: e9365368b483)

Note: The patch differs from the upstream commit:
---
1:  9ab5cf19fb0e4 ! 1:  92a2aab3e8a99 net: fix crash when config small gso_max_size/gso_ipv4_max_size
    @@ Metadata
      ## Commit message ##
         net: fix crash when config small gso_max_size/gso_ipv4_max_size
     
    +    [ 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.
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://patch.msgid.link/20241023035213.517386-1-wangliang74@huawei.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    [ Resolve minor conflicts to fix CVE-2024-50258 ]
    +    Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
    +    Signed-off-by: Sasha Levin <sashal@kernel.org>
    +    [Harshit: Clean cherrypick from 6.1.y commit]
    +    Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
     
      ## net/core/rtnetlink.c ##
     @@ net/core/rtnetlink.c: static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
    @@ net/core/rtnetlink.c: static const struct nla_policy ifla_policy[IFLA_MAX+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 },
    -@@ net/core/rtnetlink.c: 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 },
    - };
    - 
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |