CVE-2025-39979
- Published: 2025-10-15T08:15:35.767
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:
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
Related CVE by CWE
No related CWE found.
Top CVE for Vendor
No vendor taxonomy on this entry.
Recently Exploited Similar Vulnerabilities
No recent KEV-listed items for this vendor/product.
How to fix CVE-2025-39979
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 […]
Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public
How to Fix:
- Check if you're running the affected product
- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access
- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)
- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations
Exploit Difficulty Assessment
Vulnerability Timeline
CVE details first published to NVD database
Added to this CVE tracking system
Detection Rules & IOCs
No specific detection rules generated for this vulnerability type.
No vendor/product data available.