CVE-2021-47199

net/mlx5e: CT, Fix multiple allocations and memleak of mod acts

MEDIUM
5.5
CVSS Score
Published: April 10, 2024 at 06:56 PM UTC
Updated: June 17, 2026 at 04:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: CT, Fix multiple allocations and memleak of mod acts CT clear action offload adds additional mod hdr actions to the flow's original mod actions in order to clear the registers which hold ct_state. When such flow also includes encap action, a neigh update event can cause the driver to unoffload the flow and then reoffload it. Each time this happens, the ct clear handling adds that same set of mod hdr actions to reset ct_state until the max of mod hdr actions is reached. Also the driver never releases the allocated mod hdr actions and causing a memleak. Fix above two issues by moving CT clear mod acts allocation into the parsing actions phase and only use it when offloading the rule. The release of mod acts will be done in the normal flow_put(). backtrace: [<000000007316e2f3>] krealloc+0x83/0xd0 [<00000000ef157de1>] mlx5e_mod_hdr_alloc+0x147/0x300 [mlx5_core] [<00000000970ce4ae>] mlx5e_tc_match_to_reg_set_and_get_id+0xd7/0x240 [mlx5_core] [<0000000067c5fa17>] mlx5e_tc_match_to_reg_set+0xa/0x20 [mlx5_core] [<00000000d032eb98>] mlx5_tc_ct_entry_set_registers.isra.0+0x36/0xc0 [mlx5_core] [<00000000fd23b869>] mlx5_tc_ct_flow_offload+0x272/0x1f10 [mlx5_core] [<000000004fc24acc>] mlx5e_tc_offload_fdb_rules.part.0+0x150/0x620 [mlx5_core] [<00000000dc741c17>] mlx5e_tc_encap_flows_add+0x489/0x690 [mlx5_core] [<00000000e92e49d7>] mlx5e_rep_update_flows+0x6e4/0x9b0 [mlx5_core] [<00000000f60f5602>] mlx5e_rep_neigh_update+0x39a/0x5d0 [mlx5_core]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.7 ≤ v < 5.15.55.7 ≤ v < 5.161ef3018f5af3da6376fae546e4dfc3f05f0638155.16 rc1
Vendor states this is fixed in 486e8de6e233ff2999493533c6259d1cb538653b (fixed)
Vendor states this is fixed in 806401c20a0f9c51b6c8fd7035671e6ca841f6c2 (fixed)
Vendor states this is fixed in 5.15.5 (unaffected)
Vendor states this is fixed in 5.16 (unaffected)
Vendor states this is fixed in 5.7 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/486e8de6e233ff2999493533c6259d1cb538653b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/806401c20a0f9c51b6c8fd7035671e6ca841f6c2

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-401

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