First published: Fri Dec 27 2024(Updated: )
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.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Software | Affected Version | How to fix |
---|---|---|
Linux kernel | >=6.4<6.6.66 | |
Linux kernel | >=6.7<6.12.5 | |
Linux kernel | =6.13-rc1 | |
Linux Kernel | >=6.4<6.6.66 | |
Linux Kernel | >=6.7<6.12.5 | |
Linux Kernel | =6.13-rc1 | |
debian/linux | 5.10.223-1 5.10.234-1 6.1.129-1 6.1.133-1 6.12.21-1 6.12.22-1 |
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The severity of CVE-2024-56649 is classified as medium, as it may lead to improper configuration in the Linux kernel.
To fix CVE-2024-56649, update the Linux kernel to versions later than 6.6.66, between 6.7 and 6.12.5, or to 6.13-rc1.
CVE-2024-56649 affects multiple versions of the Linux kernel including versions from 6.4 to 6.6.66 and 6.7 to 6.12.5.
CVE-2024-56649 involves the enetc PF and VF drivers which share functionality for configuring MQPRIO.
Currently, there are no known workarounds for CVE-2024-56649, and updating the kernel is the recommended action.