Linux Kernel up to 6.18.52/7.2.6/7.3-rc2 mlxsw mlxsw_sp1_ptp_ht_gc_collect race condition

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6.2	$0-$5k	0.00+

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.52/7.2.6/7.3-rc2. Affected is the function mlxsw_sp1_ptp_ht_gc_collect of the component mlxsw. This manipulation causes race condition. The identification of this vulnerability is CVE-2026-98050. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.52/7.2.6/7.3-rc2. It has been declared as critical. Affected by this vulnerability is the function mlxsw_sp1_ptp_ht_gc_collect of the component mlxsw. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_ptp: Fix napi_gro_receive() call from GC workqueue context Currently mlxsw_sp1_ptp_ht_gc_collect() is run from the PTP garbage-collection workqueue, rather than the NAPI poll context. For any unmatched PTP entries carrying an SKB, it calls mlxsw_sp1_ptp_unmatched_finish() -> mlxsw_sp1_ptp_packet_finish(). For ingress packets, this calls mlxsw_sp_rx_listener_no_mark_func(). The end of that function is the following: skb->protocol = eth_type_trans(skb, skb->dev); napi_gro_receive(mlxsw_skb_cb(skb)->rx_md_info.napi, skb); The napi pointer is one that was placed in the SKB control block when the trapped packet was received in the NAPI context. Later, when the GC reaps the unmatched entry (up to MLXSW_SP1_PTP_HT_GC_TIMEOUT later), the call to napi_gro_receive() mutates the NAPI instance's GRO list, which is unsafe if the poll is running concurrently on another CPU. In mlxsw_sp1_ptp_ht_gc_collect(), local_bh_disable() is called to prevent softirq processing, but this only applies to the local CPU. Additionally, its comment is stale. It states that mlxsw_sp1_ptp_unmatched_finish() invokes netif_receive_skb(). This has not been accurate since the referenced commit; this patch makes that comment accurate again. mlxsw_pci_napi_devs_init() calls netif_threaded_enable() on the NAPI RX net_device without any conditions. The NAPI instance's poll, which may be running concurrent to the GC, is running as an independently-scheduled kthread which may be on a different CPU. The call to local_bh_disable() does not guard against this. If a tx-timestamp timeout produces an unmatched entry (which can be easily reproduced by running ptp4l and waiting for a port to reach the UNCALIBRATED/SLAVE state) while the owning NAPI thread is in the middle of a poll on another CPU, both sides mutate the GRO list concurrently, as shown below: [39.846] port 1 (swp1): MASTER to UNCALIBRATED on RS_SLAVE list_add corruption. next->prev should be prev (ffff8d620faf4138), but was ffff8d624150f700. (next=ffff8d620faf4138). kernel BUG at lib/list_debug.c:29! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 1 UID: 0 PID: 539 Comm: napi/mlxsw_rx-0 Not tainted 6.18.48 #1-NixOS PREEMPT(lazy) Hardware name: Mellanox Technologies Ltd. MSN2410/VMOD0001, BIOS 4.6.5 09/13/2018 RIP: 0010:__list_add_valid_or_report+0x79/0xb0 RSP: 0018:ffffcdf8c0f27c08 EFLAGS: 00010246 RAX: 0000000000000075 RBX: ffff8d624150fd00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8d6315d1e540 RBP: ffff8d620faf4070 R08: 0000000000000000 R09: 00000000ffffdfff R10: ffffffffa5c60fe0 R11: ffffcdf8c0f27ab8 R12: 0000000000000003 R13: 000000000000003d R14: 00000000000001bc R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8d636f63f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562689a60c24 CR3: 000000015f224004 CR4: 00000000001726f0 Call Trace: <TASK> gro_receive_skb+0xee/0x230 mlxsw_sp1_ptp_got_packet+0x61/0x140 [mlxsw_spectrum] mlxsw_core_skb_receive+0xdf/0x1b0 [mlxsw_core] mlxsw_pci_napi_poll_cq_rx+0x780/0x9d0 [mlxsw_pci] __napi_poll+0x31/0x1e0 napi_threaded_poll_loop+0x16b/0x1c0 napi_threaded_poll+0x71/0xa0 kthread+0xfb/0x260 ret_from_fork+0x22d/0x260 ret_from_fork_asm+0x1a/0x30 </TASK> Kernel panic - not syncing: Fatal exception in interrupt The machinery that leads to this kernel panic has not been changed between 6.18.48 and mainline. This patch adds an ingress-delivery helper for the PTP packet_finish() path that calls netif_receive_skb() instead of napi_gro_receive(). netif_receive_skb(), unlike napi_gro_receive(), can be called from outside of the NAPI instance's poll context, which can occur at the call site for this path. RX stats accounting and the skb->dev assignment are still preserved; the only change is the delivery call itself. This removes GR ---truncated---

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-98050 since 09/25/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 6.18.53, 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch 4375b3d1c2898886df1f908160c7004bdd938e73/7ddcc460176eb34f9bc5bda3cc274d0d24dc62a9/2ac174dfcdde399fa95ba889541fb5e688d8bb35 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 6.18.51
• 6.18.52
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1
• 7.3-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.53/7.2.7/7.3-rc3
Patch: 4375b3d1c2898886df1f908160c7004bdd938e73/7ddcc460176eb34f9bc5bda3cc274d0d24dc62a9/2ac174dfcdde399fa95ba889541fb5e688d8bb35

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98050 (🔒)
GCVE (CVE): GCVE-0-2026-98050
GCVE (VulDB): GCVE-100-410299

Entryinfo

Created: 09/25/2026 16:34
Changes: 09/25/2026 16:34 (59)
Complete: 🔍
Cache ID: 216::103

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