cve/published/2024/CVE-2024-50252.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2024-50252: mlxsw: spectrum_ipip: Fix memory leak when changing remote IPv6 address

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

mlxsw: spectrum_ipip: Fix memory leak when changing remote IPv6 address

The device stores IPv6 addresses that are used for encapsulation in
linear memory that is managed by the driver.

Changing the remote address of an ip6gre net device never worked
properly, but since cited commit the following reproducer [1] would
result in a warning [2] and a memory leak [3]. The problem is that the
new remote address is never added by the driver to its hash table (and
therefore the device) and the old address is never removed from it.

Fix by programming the new address when the configuration of the ip6gre
net device changes and removing the old one. If the address did not
change, then the above would result in increasing the reference count of
the address and then decreasing it.

[1]
 # ip link add name bla up type ip6gre local 2001:db8:1::1 remote 2001:db8:2::1 tos inherit ttl inherit
 # ip link set dev bla type ip6gre remote 2001:db8:3::1
 # ip link del dev bla
 # devlink dev reload pci/0000:01:00.0

[2]
WARNING: CPU: 0 PID: 1682 at drivers/net/ethernet/mellanox/mlxsw/spectrum.c:3002 mlxsw_sp_ipv6_addr_put+0x140/0x1d0
Modules linked in:
CPU: 0 UID: 0 PID: 1682 Comm: ip Not tainted 6.12.0-rc3-custom-g86b5b55bc835 #151
Hardware name: Nvidia SN5600/VMOD0013, BIOS 5.13 05/31/2023
RIP: 0010:mlxsw_sp_ipv6_addr_put+0x140/0x1d0
[...]
Call Trace:
 <TASK>
 mlxsw_sp_router_netdevice_event+0x55f/0x1240
 notifier_call_chain+0x5a/0xd0
 call_netdevice_notifiers_info+0x39/0x90
 unregister_netdevice_many_notify+0x63e/0x9d0
 rtnl_dellink+0x16b/0x3a0
 rtnetlink_rcv_msg+0x142/0x3f0
 netlink_rcv_skb+0x50/0x100
 netlink_unicast+0x242/0x390
 netlink_sendmsg+0x1de/0x420
 ____sys_sendmsg+0x2bd/0x320
 ___sys_sendmsg+0x9a/0xe0
 __sys_sendmsg+0x7a/0xd0
 do_syscall_64+0x9e/0x1a0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

[3]
unreferenced object 0xffff898081f597a0 (size 32):
  comm "ip", pid 1626, jiffies 4294719324
  hex dump (first 32 bytes):
    20 01 0d b8 00 02 00 00 00 00 00 00 00 00 00 01   ...............
    21 49 61 83 80 89 ff ff 00 00 00 00 01 00 00 00  !Ia.............
  backtrace (crc fd9be911):
    [<00000000df89c55d>] __kmalloc_cache_noprof+0x1da/0x260
    [<00000000ff2a1ddb>] mlxsw_sp_ipv6_addr_kvdl_index_get+0x281/0x340
    [<000000009ddd445d>] mlxsw_sp_router_netdevice_event+0x47b/0x1240
    [<00000000743e7757>] notifier_call_chain+0x5a/0xd0
    [<000000007c7b9e13>] call_netdevice_notifiers_info+0x39/0x90
    [<000000002509645d>] register_netdevice+0x5f7/0x7a0
    [<00000000c2e7d2a9>] ip6gre_newlink_common.isra.0+0x65/0x130
    [<0000000087cd6d8d>] ip6gre_newlink+0x72/0x120
    [<000000004df7c7cc>] rtnl_newlink+0x471/0xa20
    [<0000000057ed632a>] rtnetlink_rcv_msg+0x142/0x3f0
    [<0000000032e0d5b5>] netlink_rcv_skb+0x50/0x100
    [<00000000908bca63>] netlink_unicast+0x242/0x390
    [<00000000cdbe1c87>] netlink_sendmsg+0x1de/0x420
    [<0000000011db153e>] ____sys_sendmsg+0x2bd/0x320
    [<000000003b6d53eb>] ___sys_sendmsg+0x9a/0xe0
    [<00000000cae27c62>] __sys_sendmsg+0x7a/0xd0

The Linux kernel CVE team has assigned CVE-2024-50252 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.17 with commit cf42911523e02026cb56d329e584ae5923e94ba1 and fixed in 6.1.116 with commit d8f298eb6659eb6a38e26b79e77de4449dc6e61b
	Issue introduced in 5.17 with commit cf42911523e02026cb56d329e584ae5923e94ba1 and fixed in 6.6.60 with commit 31384aa2ad05c29c7745000f321154f42de24d1a
	Issue introduced in 5.17 with commit cf42911523e02026cb56d329e584ae5923e94ba1 and fixed in 6.11.7 with commit c1bbdbe07f0bc3bc9f87efe4672d67208c6d6942
	Issue introduced in 5.17 with commit cf42911523e02026cb56d329e584ae5923e94ba1 and fixed in 6.12 with commit 12ae97c531fcd3bfd774d4dfeaeac23eafe24280

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-50252
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d8f298eb6659eb6a38e26b79e77de4449dc6e61b
	https://git.kernel.org/stable/c/31384aa2ad05c29c7745000f321154f42de24d1a
	https://git.kernel.org/stable/c/c1bbdbe07f0bc3bc9f87efe4672d67208c6d6942
	https://git.kernel.org/stable/c/12ae97c531fcd3bfd774d4dfeaeac23eafe24280