Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: TC, Fix using eswitch mapping in nic mode Cited patch is using the eswitch object mapping pool while in nic mode where it isn't initialized. This results in the trace below [0]. Fix that by using either nic or eswitch object mapping pool depending if eswitch is enabled or not. [0]: [ 826.446057] ================================================================== [ 826.446729] BUG: KASAN: slab-use-after-free in mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.447515] Read of size 8 at addr ffff888194485830 by task tc/6233 [ 826.448243] CPU: 16 PID: 6233 Comm: tc Tainted: G W 6.3.0-rc6+ #1 [ 826.448890] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 826.449785] Call Trace: [ 826.450052] <TASK> [ 826.450302] dump_stack_lvl+0x33/0x50 [ 826.450650] print_report+0xc2/0x610 [ 826.450998] ? __virt_addr_valid+0xb1/0x130 [ 826.451385] ? mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.451935] kasan_report+0xae/0xe0 [ 826.452276] ? mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.452829] mlx5_add_flow_rules+0x30/0x490 [mlx5_core] [ 826.453368] ? __kmalloc_node+0x5a/0x120 [ 826.453733] esw_add_restore_rule+0x20f/0x270 [mlx5_core] [ 826.454288] ? mlx5_eswitch_add_send_to_vport_meta_rule+0x260/0x260 [mlx5_core] [ 826.455011] ? mutex_unlock+0x80/0xd0 [ 826.455361] ? __mutex_unlock_slowpath.constprop.0+0x210/0x210 [ 826.455862] ? mapping_add+0x2cb/0x440 [mlx5_core] [ 826.456425] mlx5e_tc_action_miss_mapping_get+0x139/0x180 [mlx5_core] [ 826.457058] ? mlx5e_tc_update_skb_nic+0xb0/0xb0 [mlx5_core] [ 826.457636] ? __kasan_kmalloc+0x77/0x90 [ 826.458000] ? __kmalloc+0x57/0x120 [ 826.458336] mlx5_tc_ct_flow_offload+0x325/0xe40 [mlx5_core] [ 826.458916] ? ct_kernel_enter.constprop.0+0x48/0xa0 [ 826.459360] ? mlx5_tc_ct_parse_action+0xf0/0xf0 [mlx5_core] [ 826.459933] ? mlx5e_mod_hdr_attach+0x491/0x520 [mlx5_core] [ 826.460507] ? mlx5e_mod_hdr_get+0x12/0x20 [mlx5_core] [ 826.461046] ? mlx5e_tc_attach_mod_hdr+0x154/0x170 [mlx5_core] [ 826.461635] mlx5e_configure_flower+0x969/0x2110 [mlx5_core] [ 826.462217] ? _raw_spin_lock_bh+0x85/0xe0 [ 826.462597] ? __mlx5e_add_fdb_flow+0x750/0x750 [mlx5_core] [ 826.463163] ? kasan_save_stack+0x2e/0x40 [ 826.463534] ? down_read+0x115/0x1b0 [ 826.463878] ? down_write_killable+0x110/0x110 [ 826.464288] ? tc_setup_action.part.0+0x9f/0x3b0 [ 826.464701] ? mlx5e_is_uplink_rep+0x4c/0x90 [mlx5_core] [ 826.465253] ? mlx5e_tc_reoffload_flows_work+0x130/0x130 [mlx5_core] [ 826.465878] tc_setup_cb_add+0x112/0x250 [ 826.466247] fl_hw_replace_filter+0x230/0x310 [cls_flower] [ 826.466724] ? fl_hw_destroy_filter+0x1a0/0x1a0 [cls_flower] [ 826.467212] fl_change+0x14e1/0x2030 [cls_flower] [ 826.467636] ? sock_def_readable+0x89/0x120 [ 826.468019] ? fl_tmplt_create+0x2d0/0x2d0 [cls_flower] [ 826.468509] ? kasan_unpoison+0x23/0x50 [ 826.468873] ? get_random_u16+0x180/0x180 [ 826.469244] ? __radix_tree_lookup+0x2b/0x130 [ 826.469640] ? fl_get+0x7b/0x140 [cls_flower] [ 826.470042] ? fl_mask_put+0x200/0x200 [cls_flower] [ 826.470478] ? __mutex_unlock_slowpath.constprop.0+0x210/0x210 [ 826.470973] ? fl_tmplt_create+0x2d0/0x2d0 [cls_flower] [ 826.471427] tc_new_tfilter+0x644/0x1050 [ 826.471795] ? tc_get_tfilter+0x860/0x860 [ 826.472170] ? __thaw_task+0x130/0x130 [ 826.472525] ? arch_stack_walk+0x98/0xf0 [ 826.472892] ? cap_capable+0x9f/0xd0 [ 826.473235] ? security_capable+0x47/0x60 [ 826.473608] rtnetlink_rcv_msg+0x1d5/0x550 [ 826.473985] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 826.474383] ? __stack_depot_save+0x35/0x4c0 [ 826.474779] ? kasan_save_stack+0x2e/0x40 [ 826.475149] ? kasan_save_stack+0x1e/0x40 [ 826.475518] ? __kasan_record_aux_stack+0x9f/0xb0 [ 826.475939] ? task_work_add+0x77/0x1c0 [ 826.476305] netlink_rcv_skb+0xe0/0x210 ---truncated---

References 2

• git.kernel.org https://git.kernel.org/stable/c/4150441c010dec36abc389828e2e4758bd8ad4b3
• git.kernel.org https://git.kernel.org/stable/c/dfa1e46d6093831b9d49f0f350227a1d13644a2f

Remediation