Subject: CVE-2022-48746: net/mlx5e: Fix handling of wrong devices during bond netevent

From: Greg Kroah-Hartman <[email-masked]>

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

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

net/mlx5e: Fix handling of wrong devices during bond netevent

Current implementation of bond netevent handler only check if
the handled netdev is VF representor and it missing a check if
the VF representor is on the same phys device of the bond handling
the netevent.

Fix by adding the missing check and optimizing the check if
the netdev is VF representor so it will not access uninitialized
private data and crashes.

BUG: kernel NULL pointer dereference, address: 000000000000036c
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
Workqueue: eth3bond0 bond_mii_monitor [bonding]
RIP: 0010:mlx5e_is_uplink_rep+0xc/0x50 [mlx5_core]
RSP: 0018:ffff88812d69fd60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8881cf800000 RCX: 0000000000000000
RDX: ffff88812d69fe10 RSI: 000000000000001b RDI: ffff8881cf800880
RBP: ffff8881cf800000 R08: 00000445cabccf2b R09: 0000000000000008
R10: 0000000000000004 R11: 0000000000000008 R12: ffff88812d69fe10
R13: 00000000fffffffe R14: ffff88820c0f9000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88846fb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000036c CR3: 0000000103d80006 CR4: 0000000000370ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mlx5e_eswitch_uplink_rep+0x31/0x40 [mlx5_core]
 mlx5e_rep_is_lag_netdev+0x94/0xc0 [mlx5_core]
 mlx5e_rep_esw_bond_netevent+0xeb/0x3d0 [mlx5_core]
 raw_notifier_call_chain+0x41/0x60
 call_netdevice_notifiers_info+0x34/0x80
 netdev_lower_state_changed+0x4e/0xa0
 bond_mii_monitor+0x56b/0x640 [bonding]
 process_one_work+0x1b9/0x390
 worker_thread+0x4d/0x3d0
 ? rescuer_thread+0x350/0x350
 kthread+0x124/0x150
 ? set_kthread_struct+0x40/0x40
 ret_from_fork+0x1f/0x30

The Linux kernel CVE team has assigned CVE-2022-48746 to this issue.

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

	Issue introduced in 5.8 with commit 7e51891a237f and fixed in 5.10.97 with commit a01ee1b8165f
	Issue introduced in 5.8 with commit 7e51891a237f and fixed in 5.15.20 with commit fe70126da606
	Issue introduced in 5.8 with commit 7e51891a237f and fixed in 5.16.6 with commit 4fad499d7fec
	Issue introduced in 5.8 with commit 7e51891a237f and fixed in 5.17 with commit ec41332e02bd

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-2022-48746
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/mlx5/core/en/rep/bond.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/a01ee1b8165f4161459b5ec4e728bc7130fe8cd4
	https://git.kernel.org/stable/c/fe70126da6063c29ca161cdec7ad1dae9af836b3
	https://git.kernel.org/stable/c/4fad499d7fece448e7230d5e5b92f6d8a073e0bb
	https://git.kernel.org/stable/c/ec41332e02bd0acf1f24206867bb6a02f5877a62