CVE-2024-56649

In the Linux kernel, the following vulnerability has been resolved: net: enetc: Do not configure preemptible TCs if SIs do not support Both ENETC PF and VF drivers share enetc_setup_tc_mqprio() to configure MQPRIO. And enetc_setup_tc_mqprio() calls enetc_change_preemptible_tcs() to configure preemptible TCs. However, only PF is able to configure preemptible TCs. Because only PF has related registers, while VF does not have these registers. So for VF, its hw->port pointer is NULL. Therefore, VF will access an invalid pointer when accessing a non-existent register, which will cause a crash issue. The simplified log is as follows. root@ls1028ardb:~# tc qdisc add dev eno0vf0 parent root handle 100: \ mqprio num_tc 4 map 0 0 1 1 2 2 3 3 queues 1@0 1@1 1@2 1@3 hw 1 [ 187.290775] Unable to handle kernel paging request at virtual address 0000000000001f00 [ 187.424831] pc : enetc_mm_commit_preemptible_tcs+0x1c4/0x400 [ 187.430518] lr : enetc_mm_commit_preemptible_tcs+0x30c/0x400 [ 187.511140] Call trace: [ 187.513588] enetc_mm_commit_preemptible_tcs+0x1c4/0x400 [ 187.518918] enetc_setup_tc_mqprio+0x180/0x214 [ 187.523374] enetc_vf_setup_tc+0x1c/0x30 [ 187.527306] mqprio_enable_offload+0x144/0x178 [ 187.531766] mqprio_init+0x3ec/0x668 [ 187.535351] qdisc_create+0x15c/0x488 [ 187.539023] tc_modify_qdisc+0x398/0x73c [ 187.542958] rtnetlink_rcv_msg+0x128/0x378 [ 187.547064] netlink_rcv_skb+0x60/0x130 [ 187.550910] rtnetlink_rcv+0x18/0x24 [ 187.554492] netlink_unicast+0x300/0x36c [ 187.558425] netlink_sendmsg+0x1a8/0x420 [ 187.606759] ---[ end trace 0000000000000000 ]--- In addition, some PFs also do not support configuring preemptible TCs, such as eno1 and eno3 on LS1028A. It won't crash like it does for VFs, but we should prevent these PFs from accessing these unimplemented registers.

The following products are affected by CVE-2024-56649 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2024-56649.

URL	Resource
https://git.kernel.org/stable/c/66127f0d1ecf00604aeab71132bde398fd9ec7c9
https://git.kernel.org/stable/c/b2420b8c81ec674552d00c55d46245e5c184b260
https://git.kernel.org/stable/c/b718b68a9964181e24d15138a09ce95785a19002
https://lore.kernel.org/linux-cve-announce/2024122739-CVE-2024-56649-33a6@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2024-56649
https://www.cve.org/CVERecord?id=CVE-2024-56649