CVE-2023-52851

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) …