{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98050", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:19:56.072Z", "datePublished": "2026-09-25T10:23:59.198Z", "dateUpdated": "2026-09-25T14:41:57.023Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-25T14:41:57.023Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmlxsw: spectrum_ptp: Fix napi_gro_receive() call from GC workqueue context\n\nCurrently mlxsw_sp1_ptp_ht_gc_collect() is run from the PTP\ngarbage-collection workqueue, rather than the NAPI poll context. For any\nunmatched PTP entries carrying an SKB, it calls\nmlxsw_sp1_ptp_unmatched_finish() -> mlxsw_sp1_ptp_packet_finish(). For\ningress packets, this calls mlxsw_sp_rx_listener_no_mark_func(). The end\nof that function is the following:\n\n skb->protocol = eth_type_trans(skb, skb->dev);\n napi_gro_receive(mlxsw_skb_cb(skb)->rx_md_info.napi, skb);\n\nThe napi pointer is one that was placed in the SKB control block when the\ntrapped packet was received in the NAPI context. Later, when the GC reaps\nthe unmatched entry (up to MLXSW_SP1_PTP_HT_GC_TIMEOUT later), the call to\nnapi_gro_receive() mutates the NAPI instance's GRO list, which is unsafe\nif the poll is running concurrently on another CPU.\n\nIn mlxsw_sp1_ptp_ht_gc_collect(), local_bh_disable() is called to prevent\nsoftirq processing, but this only applies to the local CPU. Additionally,\nits comment is stale. It states that mlxsw_sp1_ptp_unmatched_finish()\ninvokes netif_receive_skb(). This has not been accurate since the\nreferenced commit; this patch makes that comment accurate again.\nmlxsw_pci_napi_devs_init() calls netif_threaded_enable() on the NAPI RX\nnet_device without any conditions. The NAPI instance's poll, which may be\nrunning concurrent to the GC, is running as an independently-scheduled\nkthread which may be on a different CPU. The call to local_bh_disable()\ndoes not guard against this.\n\nIf a tx-timestamp timeout produces an unmatched entry (which can be easily\nreproduced by running ptp4l and waiting for a port to reach the\nUNCALIBRATED/SLAVE state) while the owning NAPI thread is in the middle of\na poll on another CPU, both sides mutate the GRO list concurrently, as\nshown below:\n\n [39.846] port 1 (swp1): MASTER to UNCALIBRATED on RS_SLAVE\n list_add corruption. next->prev should be prev (ffff8d620faf4138), but was ffff8d624150f700. (next=ffff8d620faf4138).\n kernel BUG at lib/list_debug.c:29!\n Oops: invalid opcode: 0000 [#1] SMP PTI\n CPU: 1 UID: 0 PID: 539 Comm: napi/mlxsw_rx-0 Not tainted 6.18.48 #1-NixOS PREEMPT(lazy)\n Hardware name: Mellanox Technologies Ltd. MSN2410/VMOD0001, BIOS 4.6.5 09/13/2018\n RIP: 0010:__list_add_valid_or_report+0x79/0xb0\n RSP: 0018:ffffcdf8c0f27c08 EFLAGS: 00010246\n RAX: 0000000000000075 RBX: ffff8d624150fd00 RCX: 0000000000000000\n RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8d6315d1e540\n RBP: ffff8d620faf4070 R08: 0000000000000000 R09: 00000000ffffdfff\n R10: ffffffffa5c60fe0 R11: ffffcdf8c0f27ab8 R12: 0000000000000003\n R13: 000000000000003d R14: 00000000000001bc R15: 0000000000000001\n FS: 0000000000000000(0000) GS:ffff8d636f63f000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000562689a60c24 CR3: 000000015f224004 CR4: 00000000001726f0\n Call Trace:\n \n gro_receive_skb+0xee/0x230\n mlxsw_sp1_ptp_got_packet+0x61/0x140 [mlxsw_spectrum]\n mlxsw_core_skb_receive+0xdf/0x1b0 [mlxsw_core]\n mlxsw_pci_napi_poll_cq_rx+0x780/0x9d0 [mlxsw_pci]\n __napi_poll+0x31/0x1e0\n napi_threaded_poll_loop+0x16b/0x1c0\n napi_threaded_poll+0x71/0xa0\n kthread+0xfb/0x260\n ret_from_fork+0x22d/0x260\n ret_from_fork_asm+0x1a/0x30\n \n Kernel panic - not syncing: Fatal exception in interrupt\n\nThe machinery that leads to this kernel panic has not been changed between\n6.18.48 and mainline.\n\nThis patch adds an ingress-delivery helper for the PTP packet_finish()\npath that calls netif_receive_skb() instead of napi_gro_receive().\nnetif_receive_skb(), unlike napi_gro_receive(), can be called from outside\nof the NAPI instance's poll context, which can occur at the call site for\nthis path. RX stats accounting and the skb->dev assignment are still\npreserved; the only change is the delivery call itself.\n\nThis removes GR\n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - The unmatched entries come from PTP event frames (Sync/Delay_Req/Pdelay) received on a Spectrum-1 port and trapped via PTP0 to mlxsw_sp1_ptp_receive(); only a peer on the port's link supplies these normally link-local PTP frames, so the range is adjacent, not routable Network.\nAC:H - Needs Spectrum-1 hardware with admin-enabled RX HW timestamping (ing_types set), an ingress skb left unmatched past MLXSW_SP1_PTP_HT_GC_TIMEOUT, and mlxsw_sp1_ptp_ht_gc_collect() calling napi_gro_receive() while the threaded NAPI poll runs on another CPU; the attacker cannot schedule that cross-CPU overlap.\nPR:N - Received PTP frames are trapped and queued in unmatched_ht without any authentication; the attacker only needs to send frames on the link, while enabling timestamping is the operator's standing configuration.\nUI:N - No victim action is needed; the GC delayed work runs every MLXSW_SP1_PTP_HT_GC_INTERVAL on its own and delivers stale ingress skbs.\nS:U - The corruption is confined to the host kernel's networking/GRO state, with no crossing of a VM or IOMMU boundary.\nC:H - Concurrent unlocked mutation of the NAPI instance's GRO skb list from the GC workqueue and the NAPI poll kthread corrupts list linkage, which can leave skbs freed while still linked (use-after-free), a primitive usable for kernel memory disclosure.\nI:H - The GRO list corruption (list_add corruption shown in gro_receive_skb) can turn into use-after-free and linked-list writes on kernel skb memory, which could be abused to corrupt kernel memory.\nA:H - The race produces list corruption detected in __list_add_valid_or_report, and the resulting BUG in the napi/mlxsw_rx kthread panics the switch kernel ('Fatal exception in interrupt')." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c" ], "versions": [ { "version": "1ba06ca96ca255c079ce5ea6a75cc0bfd5e97921", "lessThan": "4375b3d1c2898886df1f908160c7004bdd938e73", "status": "affected", "versionType": "git" }, { "version": "1ba06ca96ca255c079ce5ea6a75cc0bfd5e97921", "lessThan": "7ddcc460176eb34f9bc5bda3cc274d0d24dc62a9", "status": "affected", "versionType": "git" }, { "version": "1ba06ca96ca255c079ce5ea6a75cc0bfd5e97921", "lessThan": "2ac174dfcdde399fa95ba889541fb5e688d8bb35", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3-rc3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.3-rc3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4375b3d1c2898886df1f908160c7004bdd938e73" }, { "url": "https://git.kernel.org/stable/c/7ddcc460176eb34f9bc5bda3cc274d0d24dc62a9" }, { "url": "https://git.kernel.org/stable/c/2ac174dfcdde399fa95ba889541fb5e688d8bb35" } ], "title": "mlxsw: spectrum_ptp: Fix napi_gro_receive() call from GC workqueue context", "x_generator": { "engine": "bippy-1.2.0" } } } }