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OESA-2026-2235 (CVE-2026-31407)

Vulnerability from osv_openeuler – Published: 2026-05-09 11:11 – Updated: 2026-08-06 11:11 – Source website
VLAI
Summary
kernel security update
Details

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

netfilter: conntrack: add missing netlink policy validations

Hyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.

These attributes are used by the kernel without any validation. Extend the netlink policies accordingly.

Quoting the reporter: nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE value directly to ct->proto.sctp.state without checking that it is within the valid range. [..]

and: ... with exp->dir = 100, the access at ct->master->tuplehash[100] reads 5600 bytes past the start of a 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by UBSAN.(CVE-2026-31407)

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ipset: drop logically empty buckets in mtype_del

mtype_del() counts empty slots below n->pos in k, but it only drops the bucket when both n->pos and k are zero. This misses buckets whose live entries have all been removed while n->pos still points past deleted slots.

Treat a bucket as empty when all positions below n->pos are unused and release it directly instead of shrinking it further.(CVE-2026-31418)

In the Linux kernel, the following vulnerability has been resolved:

bridge: mrp: reject zero test interval to avoid OOM panic

br_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied interval value from netlink without validation. When interval is 0, usecs_to_jiffies(0) yields 0, causing the delayed work (br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule itself with zero delay. This creates a tight loop on system_percpu_wq that allocates and transmits MRP test frames at maximum rate, exhausting all system memory and causing a kernel panic via OOM deadlock.

The same zero-interval issue applies to br_mrp_start_in_test_parse() for interconnect test frames.

Use NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the netlink attribute parsing layer before the value ever reaches the workqueue scheduling code. This is consistent with how other bridge subsystems (br_fdb, br_mst) enforce range constraints on netlink attributes.(CVE-2026-31420)

In the Linux kernel, the following vulnerability has been resolved:

net/sched: sch_hfsc: fix divide-by-zero in rtsc_min()

m2sm() converts a u32 slope to a u64 scaled value. For large inputs (e.g. m1=4000000000), the result can reach 2^32. rtsc_min() stores the difference of two such u64 values in a u32 variable dsm and uses it as a divisor. When the difference is exactly 2^32 the truncation yields zero, causing a divide-by-zero oops in the concave-curve intersection path:

Oops: divide error: 0000 RIP: 0010:rtsc_min (net/sched/sch_hfsc.c:601) Call Trace: init_ed (net/sched/sch_hfsc.c:629) hfsc_enqueue (net/sched/sch_hfsc.c:1569) [...]

Widen dsm to u64 and replace do_div() with div64_u64() so the full difference is preserved.(CVE-2026-31423)

In the Linux kernel, the following vulnerability has been resolved:

netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP

Weiming Shi says:

xt_match and xt_target structs registered with NFPROTO_UNSPEC can be loaded by any protocol family through nft_compat. When such a match/target sets .hooks to restrict which hooks it may run on, the bitmask uses NF_INET_ constants. This is only correct for families whose hook layout matches NF_INET_: IPv4, IPv6, INET, and bridge all share the same five hooks (PRE_ROUTING ... POST_ROUTING).

ARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different semantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks validation silently passes for the wrong reasons, allowing matches to run on ARP chains where the hook assumptions (e.g. state->in being set on input hooks) do not hold. This leads to NULL pointer dereferences; xt_devgroup is one concrete example:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227] RIP: 0010:devgroup_mt+0xff/0x350 Call Trace: <TASK> nft_match_eval (net/netfilter/nft_compat.c:407) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61) nf_hook_slow (net/netfilter/core.c:623) arp_xmit (net/ipv4/arp.c:666) </TASK> Kernel panic - not syncing: Fatal exception in interrupt

Fix it by restricting arptables to NFPROTO_ARP extensions only. Note that arptables-legacy only supports:

  • arpt_CLASSIFY
  • arpt_mangle
  • arpt_MARK

that provide explicit NFPROTO_ARP match/target declarations.(CVE-2026-31424)

In the Linux kernel, the following vulnerability has been resolved:

ALSA: ctxfi: Limit PTP to a single page

Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256 playback streams, but the additional pages are not used by the card correctly. The CT20K2 hardware already has multiple VMEM_PTPAL registers, but using them separately would require refactoring the entire virtual memory allocation logic.

ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When aggregate memory allocations exceed this limit, ct_vm_map() tries to access beyond the allocated space and causes a page fault:

BUG: unable to handle page fault for address: ffffd4ae8a10a000 Oops: Oops: 0002 [#1] SMP PTI RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi] Call Trace: atc_pcm_playback_prepare+0x225/0x3b0 ct_pcm_playback_prepare+0x38/0x60 snd_pcm_do_prepare+0x2f/0x50 snd_pcm_action_single+0x36/0x90 snd_pcm_action_nonatomic+0xbf/0xd0 snd_pcm_ioctl+0x28/0x40 __x64_sys_ioctl+0x97/0xe0 do_syscall_64+0x81/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count remain unchanged.(CVE-2026-31602)

In the Linux kernel, the following vulnerability has been resolved:

net: ipv6: flowlabel: defer exclusive option free until RCU teardown

ip6fl_seq_show() walks the global flowlabel hash under the seq-file RCU read-side lock and prints fl-&gt;opt-&gt;opt_nflen when an option block is present.

Exclusive flowlabels currently free fl-&gt;opt as soon as fl-&gt;users drops to zero in fl_release(). However, the surrounding struct ip6_flowlabel remains visible in the global hash table until later garbage collection removes it and fl_free_rcu() finally tears it down.

A concurrent /proc/net/ip6_flowlabel reader can therefore race that early kfree() and dereference freed option state, triggering a crash in ip6fl_seq_show().

Fix this by keeping fl-&gt;opt alive until fl_free_rcu(). That matches the lifetime already required for the enclosing flowlabel while readers can still reach it under RCU.(CVE-2026-31680)

In the Linux kernel, the following vulnerability has been resolved:

perf/x86: Fix potential bad container_of in intel_pmu_hw_config

Auto counter reload may have a group of events with software events present within it. The software event PMU isn't the x86_hybrid_pmu and a container_of operation in intel_pmu_set_acr_caused_constr (via the hybrid helper) could cause out of bound memory reads. Avoid this by guarding the call to intel_pmu_set_acr_caused_constr with an is_x86_event check.(CVE-2026-31782)

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
To clipboard 

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    {
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          "kernel-debuginfo-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
          "kernel-debugsource-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
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          "kernel-headers-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
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          "kernel-tools-devel-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
          "perf-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
          "perf-debuginfo-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
          "python3-perf-6.6.0-145.0.9.136.oe2403.aarch64.rpm",
          "python3-perf-debuginfo-6.6.0-145.0.9.136.oe2403.aarch64.rpm"
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        ],
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          "bpftool-debuginfo-6.6.0-145.0.9.136.oe2403.x86_64.rpm",
          "kernel-6.6.0-145.0.9.136.oe2403.x86_64.rpm",
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          "events": [
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          "type": "ECOSYSTEM"
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  "database_specific": {
    "severity": "High"
  },
  "details": "The Linux Kernel, the operating system core itself.\r\n\r\nSecurity Fix(es):\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: conntrack: add missing netlink policy validations\n\nHyunwoo Kim reports out-of-bounds access in sctp and ctnetlink.\n\nThese attributes are used by the kernel without any validation.\nExtend the netlink policies accordingly.\n\nQuoting the reporter:\n  nlattr_to_sctp() assigns the user-supplied CTA_PROTOINFO_SCTP_STATE\n  value directly to ct-\u0026gt;proto.sctp.state without checking that it is\n  within the valid range. [..]\n\n  and: ... with exp-\u0026gt;dir = 100, the access at\n  ct-\u0026gt;master-\u0026gt;tuplehash[100] reads 5600 bytes past the start of a\n  320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by\n  UBSAN.(CVE-2026-31407)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ipset: drop logically empty buckets in mtype_del\n\nmtype_del() counts empty slots below n-\u0026gt;pos in k, but it only drops the\nbucket when both n-\u0026gt;pos and k are zero. This misses buckets whose live\nentries have all been removed while n-\u0026gt;pos still points past deleted slots.\n\nTreat a bucket as empty when all positions below n-\u0026gt;pos are unused and\nrelease it directly instead of shrinking it further.(CVE-2026-31418)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbridge: mrp: reject zero test interval to avoid OOM panic\n\nbr_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied\ninterval value from netlink without validation. When interval is 0,\nusecs_to_jiffies(0) yields 0, causing the delayed work\n(br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule\nitself with zero delay. This creates a tight loop on system_percpu_wq\nthat allocates and transmits MRP test frames at maximum rate, exhausting\nall system memory and causing a kernel panic via OOM deadlock.\n\nThe same zero-interval issue applies to br_mrp_start_in_test_parse()\nfor interconnect test frames.\n\nUse NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both\nIFLA_BRIDGE_MRP_START_TEST_INTERVAL and\nIFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the\nnetlink attribute parsing layer before the value ever reaches the\nworkqueue scheduling code. This is consistent with how other bridge\nsubsystems (br_fdb, br_mst) enforce range constraints on netlink\nattributes.(CVE-2026-31420)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_hfsc: fix divide-by-zero in rtsc_min()\n\nm2sm() converts a u32 slope to a u64 scaled value.  For large inputs\n(e.g. m1=4000000000), the result can reach 2^32.  rtsc_min() stores\nthe difference of two such u64 values in a u32 variable `dsm` and\nuses it as a divisor.  When the difference is exactly 2^32 the\ntruncation yields zero, causing a divide-by-zero oops in the\nconcave-curve intersection path:\n\n  Oops: divide error: 0000\n  RIP: 0010:rtsc_min (net/sched/sch_hfsc.c:601)\n  Call Trace:\n   init_ed (net/sched/sch_hfsc.c:629)\n   hfsc_enqueue (net/sched/sch_hfsc.c:1569)\n   [...]\n\nWiden `dsm` to u64 and replace do_div() with div64_u64() so the full\ndifference is preserved.(CVE-2026-31423)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP\n\nWeiming Shi says:\n\nxt_match and xt_target structs registered with NFPROTO_UNSPEC can be\nloaded by any protocol family through nft_compat. When such a\nmatch/target sets .hooks to restrict which hooks it may run on, the\nbitmask uses NF_INET_* constants. This is only correct for families\nwhose hook layout matches NF_INET_*: IPv4, IPv6, INET, and bridge\nall share the same five hooks (PRE_ROUTING ... POST_ROUTING).\n\nARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different\nsemantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks\nvalidation silently passes for the wrong reasons, allowing matches to\nrun on ARP chains where the hook assumptions (e.g. state-\u0026gt;in being\nset on input hooks) do not hold. This leads to NULL pointer\ndereferences; xt_devgroup is one concrete example:\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227]\n RIP: 0010:devgroup_mt+0xff/0x350\n Call Trace:\n  \u0026lt;TASK\u0026gt;\n  nft_match_eval (net/netfilter/nft_compat.c:407)\n  nft_do_chain (net/netfilter/nf_tables_core.c:285)\n  nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61)\n  nf_hook_slow (net/netfilter/core.c:623)\n  arp_xmit (net/ipv4/arp.c:666)\n  \u0026lt;/TASK\u0026gt;\n Kernel panic - not syncing: Fatal exception in interrupt\n\nFix it by restricting arptables to NFPROTO_ARP extensions only.\nNote that arptables-legacy only supports:\n\n- arpt_CLASSIFY\n- arpt_mangle\n- arpt_MARK\n\nthat provide explicit NFPROTO_ARP match/target declarations.(CVE-2026-31424)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: ctxfi: Limit PTP to a single page\n\nCommit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256\nplayback streams, but the additional pages are not used by the card\ncorrectly. The CT20K2 hardware already has multiple VMEM_PTPAL\nregisters, but using them separately would require refactoring the\nentire virtual memory allocation logic.\n\nct_vm_map() always uses PTEs in vm-\u0026gt;ptp[0].area regardless of\nCT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When\naggregate memory allocations exceed this limit, ct_vm_map() tries to\naccess beyond the allocated space and causes a page fault:\n\n  BUG: unable to handle page fault for address: ffffd4ae8a10a000\n  Oops: Oops: 0002 [#1] SMP PTI\n  RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi]\n  Call Trace:\n  atc_pcm_playback_prepare+0x225/0x3b0\n  ct_pcm_playback_prepare+0x38/0x60\n  snd_pcm_do_prepare+0x2f/0x50\n  snd_pcm_action_single+0x36/0x90\n  snd_pcm_action_nonatomic+0xbf/0xd0\n  snd_pcm_ioctl+0x28/0x40\n  __x64_sys_ioctl+0x97/0xe0\n  do_syscall_64+0x81/0x610\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nRevert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count\nremain unchanged.(CVE-2026-31602)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: flowlabel: defer exclusive option free until RCU teardown\n\n`ip6fl_seq_show()` walks the global flowlabel hash under the seq-file\nRCU read-side lock and prints `fl-\u0026gt;opt-\u0026gt;opt_nflen` when an option block\nis present.\n\nExclusive flowlabels currently free `fl-\u0026gt;opt` as soon as `fl-\u0026gt;users`\ndrops to zero in `fl_release()`. However, the surrounding\n`struct ip6_flowlabel` remains visible in the global hash table until\nlater garbage collection removes it and `fl_free_rcu()` finally tears it\ndown.\n\nA concurrent `/proc/net/ip6_flowlabel` reader can therefore race that\nearly `kfree()` and dereference freed option state, triggering a crash\nin `ip6fl_seq_show()`.\n\nFix this by keeping `fl-\u0026gt;opt` alive until `fl_free_rcu()`. That matches\nthe lifetime already required for the enclosing flowlabel while readers\ncan still reach it under RCU.(CVE-2026-31680)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86: Fix potential bad container_of in intel_pmu_hw_config\n\nAuto counter reload may have a group of events with software events\npresent within it. The software event PMU isn\u0026apos;t the x86_hybrid_pmu and\na container_of operation in intel_pmu_set_acr_caused_constr (via the\nhybrid helper) could cause out of bound memory reads. Avoid this by\nguarding the call to intel_pmu_set_acr_caused_constr with an\nis_x86_event check.(CVE-2026-31782)",
  "id": "OESA-2026-2235",
  "modified": "2026-08-06T11:11:12Z",
  "published": "2026-05-09T11:11:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2235"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31407"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31418"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31420"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31423"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31424"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31602"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31680"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31782"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "kernel security update",
  "upstream": [
    "CVE-2026-31407",
    "CVE-2026-31418",
    "CVE-2026-31420",
    "CVE-2026-31423",
    "CVE-2026-31424",
    "CVE-2026-31602",
    "CVE-2026-31680",
    "CVE-2026-31782"
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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