CVE-2023-53347
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Handle pairing of E-switch via uplink un/load APIs In case user switch a device from switchdev mode to legacy mode, mlx5 first unpair the E-switch and afterwards unload the uplink vport. From the other hand, in case user remove or reload a device, mlx5 first unload the uplink vport and afterwards unpair the E-switch. The latter is causing a bug[1], hence, handle pairing of E-switch as part of uplink un/load APIs. [1] In case VF_LAG is used, every tc fdb flow is duplicated to the peer esw. However, the original esw keeps a pointer to this duplicated flow, not the peer esw. e.g.: if user create tc fdb flow over esw0, the flow is duplicated over esw1, in FW/HW, but in SW, esw0 keeps a pointer to the duplicated flow. During module unload while a peer tc fdb flow is still offloaded, in case the first device to be removed is the peer device (esw1 in the example above), the peer net-dev is destroyed, and so the mlx5e_priv is memset to 0. Afterwards, the peer device is trying to unpair himself from the original device (esw0 in the example above). Unpair API invoke the original device to clear peer flow from its eswitch (esw0), but the peer flow, which is stored over the original eswitch (esw0), is trying to use the peer mlx5e_priv, which is memset to 0 and result in bellow kernel-oops. [ 157.964081 ] BUG: unable to handle page fault for address: 000000000002ce60 [ 157.964662 ] #PF: supervisor read access in kernel mode [ 157.965123 ] #PF: error_code(0x0000) - not-present page [ 157.965582 ] PGD 0 P4D 0 [ 157.965866 ] Oops: 0000 [#1] SMP [ 157.967670 ] RIP: 0010:mlx5e_tc_del_fdb_flow+0x48/0x460 [mlx5_core] [ 157.976164 ] Call Trace: [ 157.976437 ] <TASK> [ 157.976690 ] __mlx5e_tc_del_fdb_peer_flow+0xe6/0x100 [mlx5_core] [ 157.977230 ] mlx5e_tc_clean_fdb_peer_flows+0x67/0x90 [mlx5_core] [ 157.977767 ] mlx5_esw_offloads_unpair+0x2d/0x1e0 [mlx5_core] [ 157.984653 ] mlx5_esw_offloads_devcom_event+0xbf/0x130 [mlx5_core] [ 157.985212 ] mlx5_devcom_send_event+0xa3/0xb0 [mlx5_core] [ 157.985714 ] esw_offloads_disable+0x5a/0x110 [mlx5_core] [ 157.986209 ] mlx5_eswitch_disable_locked+0x152/0x170 [mlx5_core] [ 157.986757 ] mlx5_eswitch_disable+0x51/0x80 [mlx5_core] [ 157.987248 ] mlx5_unload+0x2a/0xb0 [mlx5_core] [ 157.987678 ] mlx5_uninit_one+0x5f/0xd0 [mlx5_core] [ 157.988127 ] remove_one+0x64/0xe0 [mlx5_core] [ 157.988549 ] pci_device_remove+0x31/0xa0 [ 157.988933 ] device_release_driver_internal+0x18f/0x1f0 [ 157.989402 ] driver_detach+0x3f/0x80 [ 157.989754 ] bus_remove_driver+0x70/0xf0 [ 157.990129 ] pci_unregister_driver+0x34/0x90 [ 157.990537 ] mlx5_cleanup+0xc/0x1c [mlx5_core] [ 157.990972 ] __x64_sys_delete_module+0x15a/0x250 [ 157.991398 ] ? exit_to_user_mode_prepare+0xea/0x110 [ 157.991840 ] do_syscall_64+0x3d/0x90 [ 157.992198 ] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.8 | 5.5 | 5.5 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | None | None |
| Integrity Impact | Low | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
