NULL Pointer Dereference The advisory has been revoked - it doesn't affect any version of package kernel-64k-debug-devel-matched  (opens in a new tab)

The Red Hat security team deemed this advisory irrelevant for RHEL:9.

Note: Versions mentioned in the description apply only to the upstream kernel-64k-debug-devel-matched package and not the kernel-64k-debug-devel-matched package as distributed by RHEL.

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

net/mlx5e: Fix cleanup null-ptr deref on encap lock

During module is unloaded while a peer tc flow is still offloaded, first the peer uplink rep profile is changed to a nic profile, and so neigh encap lock is destroyed. Next during unload, the VF reps netdevs are unregistered which causes the original non-peer tc flow to be deleted, which deletes the peer flow. The peer flow deletion detaches the encap entry and try to take the already destroyed encap lock, causing the below trace.

Fix this by clearing peer flows during tc eswitch cleanup (mlx5e_tc_esw_cleanup()).

Relevant trace: [ 4316.837128] BUG: kernel NULL pointer dereference, address: 00000000000001d8 [ 4316.842239] RIP: 0010:__mutex_lock+0xb5/0xc40 [ 4316.851897] Call Trace: [ 4316.852481] <TASK> [ 4316.857214] mlx5e_rep_neigh_entry_release+0x93/0x790 [mlx5_core] [ 4316.858258] mlx5e_rep_encap_entry_detach+0xa7/0xf0 [mlx5_core] [ 4316.859134] mlx5e_encap_dealloc+0xa3/0xf0 [mlx5_core] [ 4316.859867] clean_encap_dests.part.0+0x5c/0xe0 [mlx5_core] [ 4316.860605] mlx5e_tc_del_fdb_flow+0x32a/0x810 [mlx5_core] [ 4316.862609] __mlx5e_tc_del_fdb_peer_flow+0x1a2/0x250 [mlx5_core] [ 4316.863394] mlx5e_tc_del_flow+0x(/0x630 [mlx5_core] [ 4316.864090] mlx5e_flow_put+0x5f/0x100 [mlx5_core] [ 4316.864771] mlx5e_delete_flower+0x4de/0xa40 [mlx5_core] [ 4316.865486] tc_setup_cb_reoffload+0x20/0x80 [ 4316.865905] fl_reoffload+0x47c/0x510 [cls_flower] [ 4316.869181] tcf_block_playback_offloads+0x91/0x1d0 [ 4316.869649] tcf_block_unbind+0xe7/0x1b0 [ 4316.870049] tcf_block_offload_cmd.isra.0+0x1ee/0x270 [ 4316.879266] tcf_block_offload_unbind+0x61/0xa0 [ 4316.879711] __tcf_block_put+0xa4/0x310

• https://access.redhat.com/security/cve/CVE-2023-53105
• https://git.kernel.org/stable/c/01fdaea410787fe372daeaeda93a29ed0606d334
• https://git.kernel.org/stable/c/b7350f8dbe0c2a1d4d3ad7c35b610abd3cb91750
• https://git.kernel.org/stable/c/c9668f0b1d28570327dbba189f2c61f6f9e43ae7