{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-31505", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-31505" ], "published": "2026-04-22T13:57:42Z", "summary": "iavf: fix out-of-bounds writes in iavf_get_ethtool_stats()", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niavf: fix out-of-bounds writes in iavf_get_ethtool_stats()\n\niavf incorrectly uses real_num_tx_queues for ETH_SS_STATS. Since the\nvalue could change in runtime, we should use num_tx_queues instead.\n\nMoreover iavf_get_ethtool_stats() uses num_active_queues while\niavf_get_sset_count() and iavf_get_stat_strings() use\nreal_num_tx_queues, which triggers out-of-bounds writes when we do\n\"ethtool -L\" and \"ethtool -S\" simultaneously [1].\n\nFor example when we change channels from 1 to 8, Thread 3 could be\nscheduled before Thread 2, and out-of-bounds writes could be triggered\nin Thread 3:\n\nThread 1 (ethtool -L) Thread 2 (work) Thread 3 (ethtool -S)\niavf_set_channels()\n...\niavf_alloc_queues()\n-> num_active_queues = 8\niavf_schedule_finish_config()\n iavf_get_sset_count()\n real_num_tx_queues: 1\n -> buffer for 1 queue\n iavf_get_ethtool_stats()\n num_active_queues: 8\n -> out-of-bounds!\n iavf_finish_config()\n -> real_num_tx_queues = 8\n\nUse immutable num_tx_queues in all related functions to avoid the issue.\n\n[1]\n BUG: KASAN: vmalloc-out-of-bounds in iavf_add_one_ethtool_stat+0x200/0x270\n Write of size 8 at addr ffffc900031c9080 by task ethtool/5800\n\n CPU: 1 UID: 0 PID: 5800 Comm: ethtool Not tainted 6.19.0-enjuk-08403-g8137e3db7f1c #241 PREEMPT(full)\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n Call Trace:\n \n dump_stack_lvl+0x6f/0xb0\n print_report+0x170/0x4f3\n kasan_report+0xe1/0x180\n iavf_add_one_ethtool_stat+0x200/0x270\n iavf_get_ethtool_stats+0x14c/0x2e0\n __dev_ethtool+0x3d0c/0x5830\n dev_ethtool+0x12d/0x270\n dev_ioctl+0x53c/0xe30\n sock_do_ioctl+0x1a9/0x270\n sock_ioctl+0x3d4/0x5e0\n __x64_sys_ioctl+0x137/0x1c0\n do_syscall_64+0xf3/0x690\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7f7da0e6e36d\n ...\n \n\n The buggy address belongs to a 1-page vmalloc region starting at 0xffffc900031c9000 allocated at __dev_ethtool+0x3cc9/0x5830\n The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000\n index:0xffff88813a013de0 pfn:0x13a013\n flags: 0x200000000000000(node=0|zone=2)\n raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000\n raw: ffff88813a013de0 0000000000000000 00000001ffffffff 0000000000000000\n page dumped because: kasan: bad access detected\n\n Memory state around the buggy address:\n ffffc900031c8f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ffffc900031c9000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n >ffffc900031c9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ^\n ffffc900031c9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n ffffc900031c9180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null, "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-31505" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1f931dee5b726df1940348ec31614d64bac03aa6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/bb85741d2dc2be207353a412f51b83697fcbefcf" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/fdf902bf86a80bf15792a1d20a67a5302498d7f1" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/fecacfc95f195b99c71c579a472120d0b4ed65fa" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T13:16:28Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The vulnerable path is reached locally through `ioctl(SIOCETHTOOL)` on a socket, specifically `ETHTOOL_GSTATS` calling the iavf ethtool statistics callback. Remote packets may influence counter values but do not directly invoke the vulnerable code.\nAC:L - The bug is a race between attacker-issued channel reconfiguration and stats retrieval; the attacker can repeatedly run `ethtool -L` and `ethtool -S` to hit the window before `finish_config` updates `real_num_tx_queues`. No rare external condition is required.\nPR:L - `ETHTOOL_GSTATS` is allowed to any local user, but reliably creating the mismatched queue-count state requires `ETHTOOL_SCHANNELS`, gated by `ns_capable(net->user_ns, CAP_NET_ADMIN)`. In plausible delegated VF/container netns deployments this is a low namespace privilege rather than real init-namespace root.\nUI:N - No victim action is required when the attacker has the needed local namespace capability; the attacker can issue both ethtool operations directly. The vulnerable stats read itself is synchronous from the attacker\u2019s ioctl.\nS:U - The corruption occurs inside the same kernel security authority as the vulnerable network driver. This is standard kernel memory corruption/privilege escalation, not a VM escape or IOMMU boundary bypass.\nC:H - The flaw is an out-of-bounds kernel write in a vmalloc-backed stats buffer, which is memory corruption that can plausibly be leveraged during exploitation for information disclosure. Under the required conservative rule, this is High.\nI:H - The vulnerable function writes attacker-influenced u64 statistics past the allocated buffer when queue counts diverge. Out-of-bounds kernel writes are treated as high integrity impact because they can corrupt kernel memory and potentially enable code execution.\nA:H - The reported failure is a KASAN vmalloc-out-of-bounds write in kernel context, and the same corruption can oops or panic the kernel. The trigger can be repeated by local ethtool calls." } } }