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

net/mlx5: fs, fix UAF in flow counter release

Fix a kernel trace [1] caused by releasing an HWS action of a local flow
counter in mlx5_cmd_hws_delete_fte(), where the HWS action refcount and
mutex were not initialized and the counter struct could already be freed
when deleting the rule.

Fix it by adding the missing initializations and adding refcount for the
local flow counter struct.

[1] Kernel log:
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x48
mlx5_fs_put_hws_action.part.0.cold+0x21/0x94 [mlx5_core]
mlx5_fc_put_hws_action+0x96/0xad [mlx5_core]
mlx5_fs_destroy_fs_actions+0x8b/0x152 [mlx5_core]
mlx5_cmd_hws_delete_fte+0x5a/0xa0 [mlx5_core]
del_hw_fte+0x1ce/0x260 [mlx5_core]
mlx5_del_flow_rules+0x12d/0x240 [mlx5_core]
? ttwu_queue_wakelist+0xf4/0x110
mlx5_ib_destroy_flow+0x103/0x1b0 [mlx5_ib]
uverbs_free_flow+0x20/0x50 [ib_uverbs]
destroy_hw_idr_uobject+0x1b/0x50 [ib_uverbs]
uverbs_destroy_uobject+0x34/0x1a0 [ib_uverbs]
uobj_destroy+0x3c/0x80 [ib_uverbs]
ib_uverbs_run_method+0x23e/0x360 [ib_uverbs]
? uverbs_finalize_object+0x60/0x60 [ib_uverbs]
ib_uverbs_cmd_verbs+0x14f/0x2c0 [ib_uverbs]
? do_tty_write+0x1a9/0x270
? file_tty_write.constprop.0+0x98/0xc0
? new_sync_write+0xfc/0x190
ib_uverbs_ioctl+0xd7/0x160 [ib_uverbs]
__x64_sys_ioctl+0x87/0xc0
do_syscall_64+0x59/0x90
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 20 Oct 2025 13:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Thu, 16 Oct 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Wed, 15 Oct 2025 08:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net/mlx5: fs, fix UAF in flow counter release Fix a kernel trace [1] caused by releasing an HWS action of a local flow counter in mlx5_cmd_hws_delete_fte(), where the HWS action refcount and mutex were not initialized and the counter struct could already be freed when deleting the rule. Fix it by adding the missing initializations and adding refcount for the local flow counter struct. [1] Kernel log: Call Trace: <TASK> dump_stack_lvl+0x34/0x48 mlx5_fs_put_hws_action.part.0.cold+0x21/0x94 [mlx5_core] mlx5_fc_put_hws_action+0x96/0xad [mlx5_core] mlx5_fs_destroy_fs_actions+0x8b/0x152 [mlx5_core] mlx5_cmd_hws_delete_fte+0x5a/0xa0 [mlx5_core] del_hw_fte+0x1ce/0x260 [mlx5_core] mlx5_del_flow_rules+0x12d/0x240 [mlx5_core] ? ttwu_queue_wakelist+0xf4/0x110 mlx5_ib_destroy_flow+0x103/0x1b0 [mlx5_ib] uverbs_free_flow+0x20/0x50 [ib_uverbs] destroy_hw_idr_uobject+0x1b/0x50 [ib_uverbs] uverbs_destroy_uobject+0x34/0x1a0 [ib_uverbs] uobj_destroy+0x3c/0x80 [ib_uverbs] ib_uverbs_run_method+0x23e/0x360 [ib_uverbs] ? uverbs_finalize_object+0x60/0x60 [ib_uverbs] ib_uverbs_cmd_verbs+0x14f/0x2c0 [ib_uverbs] ? do_tty_write+0x1a9/0x270 ? file_tty_write.constprop.0+0x98/0xc0 ? new_sync_write+0xfc/0x190 ib_uverbs_ioctl+0xd7/0x160 [ib_uverbs] __x64_sys_ioctl+0x87/0xc0 do_syscall_64+0x59/0x90
Title net/mlx5: fs, fix UAF in flow counter release
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-15T07:55:59.609Z

Reserved: 2025-04-16T07:20:57.150Z

Link: CVE-2025-39979

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-10-15T08:15:35.767

Modified: 2025-10-16T15:29:11.563

Link: CVE-2025-39979

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-10-15T00:00:00Z

Links: CVE-2025-39979 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-10-20T13:27:13Z

Weaknesses

No weakness.