CVE-2023-53393: RDMA/mlx5: Fix mlx5_ib_get_hw_stats when used for device
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix mlx5_ib_get_hw_stats when used for device
Currently, when mlx5_ib_get_hw_stats() is used for device (port_num = 0),
there is a special handling in order to use the correct counters, but,
port_num is being passed down the stack without any change. Also, some
functions assume that port_num >=1. As a result, the following oops can
occur.
BUG: unable to handle page fault for address: ffff89510294f1a8
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP
CPU: 8 PID: 1382 Comm: devlink Tainted: G W 6.1.0-rc4_for_upstream_base_2022_11_10_16_12 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:_raw_spin_lock+0xc/0x20
Call Trace:
<TASK>
mlx5_ib_get_native_port_mdev+0x73/0xe0 [mlx5_ib]
do_get_hw_stats.constprop.0+0x109/0x160 [mlx5_ib]
mlx5_ib_get_hw_stats+0xad/0x180 [mlx5_ib]
ib_setup_device_attrs+0xf0/0x290 [ib_core]
ib_register_device+0x3bb/0x510 [ib_core]
? atomic_notifier_chain_register+0x67/0x80
__mlx5_ib_add+0x2b/0x80 [mlx5_ib]
mlx5r_probe+0xb8/0x150 [mlx5_ib]
? auxiliary_match_id+0x6a/0x90
auxiliary_bus_probe+0x3c/0x70
? driver_sysfs_add+0x6b/0x90
really_probe+0xcd/0x380
__driver_probe_device+0x80/0x170
driver_probe_device+0x1e/0x90
__device_attach_driver+0x7d/0x100
? driver_allows_async_probing+0x60/0x60
? driver_allows_async_probing+0x60/0x60
bus_for_each_drv+0x7b/0xc0
__device_attach+0xbc/0x200
bus_probe_device+0x87/0xa0
device_add+0x404/0x940
? dev_set_name+0x53/0x70
__auxiliary_device_add+0x43/0x60
add_adev+0x99/0xe0 [mlx5_core]
mlx5_attach_device+0xc8/0x120 [mlx5_core]
mlx5_load_one_devl_locked+0xb2/0xe0 [mlx5_core]
devlink_reload+0x133/0x250
devlink_nl_cmd_reload+0x480/0x570
? devlink_nl_pre_doit+0x44/0x2b0
genl_family_rcv_msg_doit.isra.0+0xc2/0x110
genl_rcv_msg+0x180/0x2b0
? devlink_nl_cmd_region_read_dumpit+0x540/0x540
? devlink_reload+0x250/0x250
? devlink_put+0x50/0x50
? genl_family_rcv_msg_doit.isra.0+0x110/0x110
netlink_rcv_skb+0x54/0x100
genl_rcv+0x24/0x40
netlink_unicast+0x1f6/0x2c0
netlink_sendmsg+0x237/0x490
sock_sendmsg+0x33/0x40
__sys_sendto+0x103/0x160
? handle_mm_fault+0x10e/0x290
? do_user_addr_fault+0x1c0/0x5f0
__x64_sys_sendto+0x25/0x30
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Fix it by setting port_num to 1 in order to get device status and remove
unused variable.
Security readout for executives and security teams
Plain-English summary
CVE-2023-53393 is a Linux kernel availability bug in the RDMA mlx5 driver path. A local, low-privileged user may be able to trigger a kernel crash when hardware statistics are requested for a device rather than a port. The impact is service disruption, not data theft or data modification.
Executive priority
Treat this as a moderate operational resilience issue. It is most relevant to Linux infrastructure using mlx5 RDMA capabilities, where a local user could cause downtime. Patch through normal kernel maintenance, with higher priority for shared compute, HPC, storage, or network-heavy hosts.
Technical view
The issue is in mlx5_ib_get_hw_stats() handling of port_num = 0. That value is passed deeper into functions that assume port_num >= 1, leading to a kernel page fault/oops. The resolved change sets port_num to 1 for device status handling and removes an unused variable.
Likely exposure
Exposure appears limited to affected Linux kernels using the RDMA mlx5 path, especially hosts with mlx5_ib or mlx5_core loaded. CVSS indicates local attack vector, low complexity, low privileges, no user interaction, and high availability impact.
Exploitation context
The source bundle does not cite active exploitation, and KEV is false. The provided stack trace shows a crash during devlink/RDMA device registration or reload handling. No public exploit evidence is included in the provided sources.
Researcher notes
The evidence supports an availability-only kernel crash from incorrect port_num handling in RDMA/mlx5 statistics code. The bundle provides fix references but no CWE, exploit report, or distribution-specific advisory. Validate exposure by kernel lineage and whether the mlx5 RDMA stack is present.
Mitigation direction
Update affected Linux kernels to versions containing the referenced stable fixes.
Prioritize RDMA or mlx5-enabled servers where local users or tenants have access.
Check distribution vendor advisories for packaged kernel update availability.
Restrict unnecessary local access on systems pending kernel updates.
Monitor for kernel oops events involving mlx5_ib_get_hw_stats or mlx5 RDMA paths.
Validation and detection
Inventory Linux kernel versions against the affected and fixed ranges in vendor guidance.
Identify hosts loading mlx5_ib or mlx5_core RDMA driver components.
Review kernel logs for oops traces mentioning mlx5_ib_get_hw_stats.
Confirm updated kernels include one of the referenced stable commits.
Verify RDMA device status collection remains stable after patching.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cve · low confidence lookup
CVE-2023-53393 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.