net/mlx5: Fix double unregister of HCA_PORTS component

published 2026-01-13 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-2289

cvss: —; not scored
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

Clear hca_devcom_comp in device's private data after unregistering it in LAG teardown. Otherwise a slightly lagging second pass through mlx5_unload_one() might try to unregister it again and trip over use-after-free.

On s390 almost all PCI level recovery events trigger two passes through mxl5_unload_one() - one through the poll_health() method and one through mlx5_pci_err_detected() as callback from generic PCI error recovery. While testing PCI error recovery paths with more kernel debug features enabled, this issue reproducibly led to kernel panics with the following call chain:

Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6803 ESOP-2 FSI Fault in home space mode while using kernel ASCE. AS:00000000705c4007 R3:0000000000000024 Oops: 0038 ilc:3 [#1]SMP

CPU: 14 UID: 0 PID: 156 Comm: kmcheck Kdump: loaded Not tainted 6.18.0-20251130.rc7.git0.16131a59cab1.300.fc43.s390x+debug #1 PREEMPT

Krnl PSW : 0404e00180000000 0000020fc86aa1dc (__lock_acquire+0x5c/0x15f0) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000000 0000020f00000001 6b6b6b6b6b6b6c33 0000000000000000 0000000000000000 0000000000000000 0000000000000001 0000000000000000 0000000000000000 0000020fca28b820 0000000000000000 0000010a1ced8100 0000010a1ced8100 0000020fc9775068 0000018fce14f8b8 0000018fce14f7f8 Krnl Code: 0000020fc86aa1cc: e3b003400004 lg %r11,832 0000020fc86aa1d2: a7840211 brc 8,0000020fc86aa5f4 *0000020fc86aa1d6: c09000df0b25 larl %r9,0000020fca28b820 >0000020fc86aa1dc: d50790002000 clc 0(8,%r9),0(%r2) 0000020fc86aa1e2: a7840209 brc 8,0000020fc86aa5f4 0000020fc86aa1e6: c0e001100401 larl %r14,0000020fca8aa9e8 0000020fc86aa1ec: c01000e25a00 larl %r1,0000020fca2f55ec 0000020fc86aa1f2: a7eb00e8 aghi %r14,232

Call Trace: __lock_acquire+0x5c/0x15f0 lock_acquire.part.0+0xf8/0x270 lock_acquire+0xb0/0x1b0 down_write+0x5a/0x250 mlx5_detach_device+0x42/0x110 [mlx5_core] mlx5_unload_one_devl_locked+0x50/0xc0 [mlx5_core] mlx5_unload_one+0x42/0x60 [mlx5_core] mlx5_pci_err_detected+0x94/0x150 [mlx5_core] zpci_event_attempt_error_recovery+0xcc/0x388

Patch / fix

fixed in 1 links 2

Linux Linux 6.18.3, 6.19

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-68790 updated 2026-11-07 cvss 5.5

kernel: net/mlx5: Fix double unregister of HCA_PORTS component

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-68790
NVD CVE-2025-68790

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary