FKIE_CVE-2026-64012

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-19 16:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_sfb: Replace direct dequeue call with peek and qdisc_dequeue_peeked When sfb has children (eg qfq qdisc) whose peek() callback is qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from its child (sfb in this case), it will do the following: 1a. do a peek() - and when sensing there's an skb the child can offer, then - the child in this case(sfb) calls its child's (qfq) peek. qfq does the right thing and will return the gso_skb queue packet. Note: if there wasnt a gso_skb entry then qfq will store it there. 1b. invoke a dequeue() on the child (sfb). And herein lies the problem. - sfb will call the child's dequeue() which will essentially just try to grab something of qfq's queue. [ 127.594489][ T453] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] [ 127.594741][ T453] CPU: 2 UID: 0 PID: 453 Comm: ping Not tainted 7.1.0-rc1-00035-gac961974495b-dirty #793 PREEMPT(full) [ 127.595059][ T453] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 127.595254][ T453] RIP: 0010:qfq_dequeue+0x35c/0x1650 [sch_qfq] [ 127.595461][ T453] Code: 00 fc ff df 80 3c 02 00 0f 85 17 0e 00 00 4c 8d 73 48 48 89 9d b8 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 76 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b [ 127.596081][ T453] RSP: 0018:ffff88810e5af440 EFLAGS: 00010216 [ 127.596337][ T453] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000 [ 127.596623][ T453] RDX: 0000000000000009 RSI: 0000001880000000 RDI: ffff888104fd82b0 [ 127.596917][ T453] RBP: ffff888104fd8000 R08: ffff888104fd8280 R09: 1ffff110211893a3 [ 127.597165][ T453] R10: 1ffff110211893a6 R11: 1ffff110211893a7 R12: 0000001880000000 [ 127.597404][ T453] R13: ffff888104fd82b8 R14: 0000000000000048 R15: 0000000040000000 [ 127.597644][ T453] FS: 00007fc380cbfc40(0000) GS:ffff88816f2a8000(0000) knlGS:0000000000000000 [ 127.597956][ T453] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 127.598160][ T453] CR2: 00005610aa9890a8 CR3: 000000010369e000 CR4: 0000000000750ef0 [ 127.598390][ T453] PKRU: 55555554 [ 127.598509][ T453] Call Trace: [ 127.598629][ T453] <TASK> [ 127.598718][ T453] ? mark_held_locks+0x40/0x70 [ 127.598890][ T453] ? srso_alias_return_thunk+0x5/0xfbef5 [ 127.599053][ T453] sfb_dequeue+0x88/0x4d0 [ 127.599174][ T453] ? ktime_get+0x137/0x230 [ 127.599328][ T453] ? srso_alias_return_thunk+0x5/0xfbef5 [ 127.599480][ T453] ? qdisc_peek_dequeued+0x7b/0x350 [sch_qfq] [ 127.599670][ T453] ? srso_alias_return_thunk+0x5/0xfbef5 [ 127.599831][ T453] tbf_dequeue+0x6b1/0x1098 [sch_tbf] [ 127.599988][ T453] __qdisc_run+0x169/0x1900 The right thing to do in #1b is to grab the skb off gso_skb queue. This patchset fixes that issue by changing #1b to use qdisc_dequeue_peeked() method instead.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1b9bc71153b01dbde8045b9edede4240f4f5520e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1e70274d3b81de28973bcdbce40a512bcb181ff9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6c153d97c100f5b282c424101d8ff63122306997
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/84bfbfc0c48731bcce74cdf4f9c497547ec525e0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9ad3288632c859cf84183199832d822e7a70bdae
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/dbc560858da8b77dd9e4ef0cd93d421e0e4d7e0e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e125f5980b730c67c92a30cf150ec8c3d6777318
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e5ea51e5f3fbba41d50cd84a530f33bc1c8f4d57
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_sfb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e5ea51e5f3fbba41d50cd84a530f33bc1c8f4d57",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "1e70274d3b81de28973bcdbce40a512bcb181ff9",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "e125f5980b730c67c92a30cf150ec8c3d6777318",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "6c153d97c100f5b282c424101d8ff63122306997",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "84bfbfc0c48731bcce74cdf4f9c497547ec525e0",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "dbc560858da8b77dd9e4ef0cd93d421e0e4d7e0e",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "9ad3288632c859cf84183199832d822e7a70bdae",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            },
            {
              "lessThan": "1b9bc71153b01dbde8045b9edede4240f4f5520e",
              "status": "affected",
              "version": "e13e02a3c68d899169c78d9a18689bd73491d59a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_sfb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.39"
            },
            {
              "lessThan": "2.6.39",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_sfb: Replace direct dequeue call with peek and qdisc_dequeue_peeked\n\nWhen sfb has children (eg qfq qdisc) whose peek() callback is\nqdisc_peek_dequeued(), we could get a kernel panic. When the parent of such\nqdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from\nits child (sfb in this case), it will do the following:\n 1a. do a peek() - and when sensing there\u0027s an skb the child can offer, then\n     - the child in this case(sfb) calls its child\u0027s (qfq) peek.\n        qfq does the right thing and will return the gso_skb queue packet.\n        Note: if there wasnt a gso_skb entry then qfq will store it there.\n 1b. invoke a dequeue() on the child (sfb). And herein lies the problem.\n     - sfb will call the child\u0027s dequeue() which will essentially just\n       try to grab something of qfq\u0027s queue.\n\n[  127.594489][  T453] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]\n[  127.594741][  T453] CPU: 2 UID: 0 PID: 453 Comm: ping Not tainted 7.1.0-rc1-00035-gac961974495b-dirty #793 PREEMPT(full)\n[  127.595059][  T453] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[  127.595254][  T453] RIP: 0010:qfq_dequeue+0x35c/0x1650 [sch_qfq]\n[  127.595461][  T453] Code: 00 fc ff df 80 3c 02 00 0f 85 17 0e 00 00 4c 8d 73 48 48 89 9d b8 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 \u003c80\u003e 3c 02 00 0f 85 76 0c 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b\n[  127.596081][  T453] RSP: 0018:ffff88810e5af440 EFLAGS: 00010216\n[  127.596337][  T453] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: dffffc0000000000\n[  127.596623][  T453] RDX: 0000000000000009 RSI: 0000001880000000 RDI: ffff888104fd82b0\n[  127.596917][  T453] RBP: ffff888104fd8000 R08: ffff888104fd8280 R09: 1ffff110211893a3\n[  127.597165][  T453] R10: 1ffff110211893a6 R11: 1ffff110211893a7 R12: 0000001880000000\n[  127.597404][  T453] R13: ffff888104fd82b8 R14: 0000000000000048 R15: 0000000040000000\n[  127.597644][  T453] FS:  00007fc380cbfc40(0000) GS:ffff88816f2a8000(0000) knlGS:0000000000000000\n[  127.597956][  T453] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  127.598160][  T453] CR2: 00005610aa9890a8 CR3: 000000010369e000 CR4: 0000000000750ef0\n[  127.598390][  T453] PKRU: 55555554\n[  127.598509][  T453] Call Trace:\n[  127.598629][  T453]  \u003cTASK\u003e\n[  127.598718][  T453]  ? mark_held_locks+0x40/0x70\n[  127.598890][  T453]  ? srso_alias_return_thunk+0x5/0xfbef5\n[  127.599053][  T453]  sfb_dequeue+0x88/0x4d0\n[  127.599174][  T453]  ? ktime_get+0x137/0x230\n[  127.599328][  T453]  ? srso_alias_return_thunk+0x5/0xfbef5\n[  127.599480][  T453]  ? qdisc_peek_dequeued+0x7b/0x350 [sch_qfq]\n[  127.599670][  T453]  ? srso_alias_return_thunk+0x5/0xfbef5\n[  127.599831][  T453]  tbf_dequeue+0x6b1/0x1098 [sch_tbf]\n[  127.599988][  T453]  __qdisc_run+0x169/0x1900\n\nThe right thing to do in #1b is to grab the skb off gso_skb queue.\nThis patchset fixes that issue by changing #1b to use qdisc_dequeue_peeked()\nmethod instead."
    }
  ],
  "id": "CVE-2026-64012",
  "lastModified": "2026-07-19T16:17:41.060",
  "metrics": {},
  "published": "2026-07-19T16:17:41.060",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1b9bc71153b01dbde8045b9edede4240f4f5520e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1e70274d3b81de28973bcdbce40a512bcb181ff9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6c153d97c100f5b282c424101d8ff63122306997"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/84bfbfc0c48731bcce74cdf4f9c497547ec525e0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9ad3288632c859cf84183199832d822e7a70bdae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dbc560858da8b77dd9e4ef0cd93d421e0e4d7e0e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e125f5980b730c67c92a30cf150ec8c3d6777318"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e5ea51e5f3fbba41d50cd84a530f33bc1c8f4d57"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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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.

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