CVE-2023-54148

Описание

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Move representor neigh cleanup to profile cleanup_tx For IP tunnel encapsulation in ECMP (Equal-Cost Multipath) mode, as the flow is duplicated to the peer eswitch, the related neighbour information on the peer uplink representor is created as well. In the cited commit, eswitch devcom unpair is moved to uplink unload API, specifically the profile->cleanup_tx. If there is a encap rule offloaded in ECMP mode, when one eswitch does unpair (because of unloading the driver, for instance), and the peer rule from the peer eswitch is going to be deleted, the use-after-free error is triggered while accessing neigh info, as it is already cleaned up in uplink's profile->disable, which is before its profile->cleanup_tx. To fix this issue, move the neigh cleanup to profile's cleanup_tx callback, and after mlx5e_cleanup_uplink_rep_tx is called. The neigh init is moved to init_tx for symmeter. [ 2453.376299] BUG: KASAN: slab-use-after-free in mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.379125] Read of size 4 at addr ffff888127af9008 by task modprobe/2496 [ 2453.381542] CPU: 7 PID: 2496 Comm: modprobe Tainted: G B 6.4.0-rc7+ #15 [ 2453.383386] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 2453.384335] Call Trace: [ 2453.384625] [ 2453.384891] dump_stack_lvl+0x33/0x50 [ 2453.385285] print_report+0xc2/0x610 [ 2453.385667] ? __virt_addr_valid+0xb1/0x130 [ 2453.386091] ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.386757] kasan_report+0xae/0xe0 [ 2453.387123] ? mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.387798] mlx5e_rep_neigh_entry_release+0x109/0x3a0 [mlx5_core] [ 2453.388465] mlx5e_rep_encap_entry_detach+0xa6/0xe0 [mlx5_core] [ 2453.389111] mlx5e_encap_dealloc+0xa7/0x100 [mlx5_core] [ 2453.389706] mlx5e_tc_tun_encap_dests_unset+0x61/0xb0 [mlx5_core] [ 2453.390361] mlx5_free_flow_attr_actions+0x11e/0x340 [mlx5_core] [ 2453.391015] ? complete_all+0x43/0xd0 [ 2453.391398] ? free_flow_post_acts+0x38/0x120 [mlx5_core] [ 2453.392004] mlx5e_tc_del_fdb_flow+0x4ae/0x690 [mlx5_core] [ 2453.392618] mlx5e_tc_del_fdb_peers_flow+0x308/0x370 [mlx5_core] [ 2453.393276] mlx5e_tc_clean_fdb_peer_flows+0xf5/0x140 [mlx5_core] [ 2453.393925] mlx5_esw_offloads_unpair+0x86/0x540 [mlx5_core] [ 2453.394546] ? mlx5_esw_offloads_set_ns_peer.isra.0+0x180/0x180 [mlx5_core] [ 2453.395268] ? down_write+0xaa/0x100 [ 2453.395652] mlx5_esw_offloads_devcom_event+0x203/0x530 [mlx5_core] [ 2453.396317] mlx5_devcom_send_event+0xbb/0x190 [mlx5_core] [ 2453.396917] mlx5_esw_offloads_devcom_cleanup+0xb0/0xd0 [mlx5_core] [ 2453.397582] mlx5e_tc_esw_cleanup+0x42/0x120 [mlx5_core] [ 2453.398182] mlx5e_rep_tc_cleanup+0x15/0x30 [mlx5_core] [ 2453.398768] mlx5e_cleanup_rep_tx+0x6c/0x80 [mlx5_core] [ 2453.399367] mlx5e_detach_netdev+0xee/0x120 [mlx5_core] [ 2453.399957] mlx5e_netdev_change_profile+0x84/0x170 [mlx5_core] [ 2453.400598] mlx5e_vport_rep_unload+0xe0/0xf0 [mlx5_core] [ 2453.403781] mlx5_eswitch_unregister_vport_reps+0x15e/0x190 [mlx5_core] [ 2453.404479] ? mlx5_eswitch_register_vport_reps+0x200/0x200 [mlx5_core] [ 2453.405170] ? up_write+0x39/0x60 [ 2453.405529] ? kernfs_remove_by_name_ns+0xb7/0xe0 [ 2453.405985] auxiliary_bus_remove+0x2e/0x40 [ 2453.406405] device_release_driver_internal+0x243/0x2d0 [ 2453.406900] ? kobject_put+0x42/0x2d0 [ 2453.407284] bus_remove_device+0x128/0x1d0 [ 2453.407687] device_del+0x240/0x550 [ 2453.408053] ? waiting_for_supplier_show+0xe0/0xe0 [ 2453.408511] ? kobject_put+0xfa/0x2d0 [ 2453.408889] ? __kmem_cache_free+0x14d/0x280 [ 2453.409310] mlx5_rescan_drivers_locked.part.0+0xcd/0x2b0 [mlx5_core] [ 2453.409973] mlx5_unregister_device+0x40/0x50 [mlx5_core] [ 2453.410561] mlx5_uninit_one+0x3d/0x110 [mlx5_core] [ 2453.411111] remove_one+0x89/0x130 [mlx5_core] [ 24 ---truncated---

A flaw was identified in the Linux kernel’s Mellanox mlx5 Ethernet driver (net/mlx5e) related to the cleanup order of neighbour information when handling offloaded IP tunnel encapsulation rules in ECMP (Equal-Cost Multipath) mode. In certain scenarios — such as unloading the eswitch device while an offloaded ECMP rule is still active — the representor neighbour data for the peer uplink may be cleaned up prematurely in the profile->disable callback before the intended profile->cleanup_tx callback. This premature cleanup can result in a use-after-free condition when subsequent code attempts to access the freed neighbour data, potentially leading to kernel faults