Subject: CVE-2023-52851: IB/mlx5: Fix init stage error handling to avoid double free of same QP and UAF

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

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

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

IB/mlx5: Fix init stage error handling to avoid double free of same QP and UAF

In the unlikely event that workqueue allocation fails and returns NULL in
mlx5_mkey_cache_init(), delete the call to
mlx5r_umr_resource_cleanup() (which frees the QP) in
mlx5_ib_stage_post_ib_reg_umr_init().  This will avoid attempted double
free of the same QP when __mlx5_ib_add() does its cleanup.

Resolves a splat:

   Syzkaller reported a UAF in ib_destroy_qp_user

   workqueue: Failed to create a rescuer kthread for wq "mkey_cache": -EINTR
   infiniband mlx5_0: mlx5_mkey_cache_init:981:(pid 1642):
   failed to create work queue
   infiniband mlx5_0: mlx5_ib_stage_post_ib_reg_umr_init:4075:(pid 1642):
   mr cache init failed -12
   ==================================================================
   BUG: KASAN: slab-use-after-free in ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073)
   Read of size 8 at addr ffff88810da310a8 by task repro_upstream/1642

   Call Trace:
   <TASK>
   kasan_report (mm/kasan/report.c:590)
   ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073)
   mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198)
   __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4178)
   mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
   ...
   </TASK>

   Allocated by task 1642:
   __kmalloc (./include/linux/kasan.h:198 mm/slab_common.c:1026
   mm/slab_common.c:1039)
   create_qp (./include/linux/slab.h:603 ./include/linux/slab.h:720
   ./include/rdma/ib_verbs.h:2795 drivers/infiniband/core/verbs.c:1209)
   ib_create_qp_kernel (drivers/infiniband/core/verbs.c:1347)
   mlx5r_umr_resource_init (drivers/infiniband/hw/mlx5/umr.c:164)
   mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4070)
   __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168)
   mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
   ...

   Freed by task 1642:
   __kmem_cache_free (mm/slub.c:1826 mm/slub.c:3809 mm/slub.c:3822)
   ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2112)
   mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198)
   mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4076
   drivers/infiniband/hw/mlx5/main.c:4065)
   __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168)
   mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402)
   ...

The Linux kernel CVE team has assigned CVE-2023-52851 to this issue.

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

	Issue introduced in 5.19 with commit 04876c12c19e and fixed in 6.1.63 with commit 437f033e30c8
	Issue introduced in 5.19 with commit 04876c12c19e and fixed in 6.5.12 with commit 4f4a7a7d1404
	Issue introduced in 5.19 with commit 04876c12c19e and fixed in 6.6.2 with commit 6387f269d84e
	Issue introduced in 5.19 with commit 04876c12c19e and fixed in 6.7 with commit 2ef422f063b7

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-2023-52851
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/infiniband/hw/mlx5/main.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/437f033e30c897bb3723eac9e9003cd9f88d00a3
	https://git.kernel.org/stable/c/4f4a7a7d1404297f2a92df0046f7e64dc5c52dd9
	https://git.kernel.org/stable/c/6387f269d84e6e149499408c4d1fc805017729b2
	https://git.kernel.org/stable/c/2ef422f063b74adcc4a4a9004b0a87bb55e0a836