CVE-2024-56649

unknown

Published — · Modified —

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

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Description

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.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

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OS impact

OS	Version	Status	Fixed in
sles		affected
debian	bookworm	fixed	`0`
debian	bullseye	fixed	`0`
debian	forky	fixed	`6.12.5-1`
debian	sid	fixed	`6.12.5-1`
debian	trixie	fixed	`6.12.5-1`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.