fkie_cve-2023-53727
Vulnerability from fkie_nvd
Published
2025-10-22 14:15
Modified
2025-10-22 21:12
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: avoid stalls in fq_pie_timer() When setting a high number of flows (limit being 65536), fq_pie_timer() is currently using too much time as syzbot reported. Add logic to yield the cpu every 2048 flows (less than 150 usec on debug kernels). It should also help by not blocking qdisc fast paths for too long. Worst case (65536 flows) would need 31 jiffies for a complete scan. Relevant extract from syzbot report: rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236 Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 <a9> 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206 RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0 RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <IRQ> pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8c21ab1bae945686c602c5bfa4e3f3352c2452c5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/94d527c3759d76c29220758362f622954612bea7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/973a4c302d7f3804098ff9824d9f56926901f293
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e093000e7d13569c9cb07d7500acd5142c3c43cb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f39b49077abec4c9c3a4c2966532004851c51006
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_pie: avoid stalls in fq_pie_timer()\n\nWhen setting a high number of flows (limit being 65536),\nfq_pie_timer() is currently using too much time as syzbot reported.\n\nAdd logic to yield the cpu every 2048 flows (less than 150 usec\non debug kernels).\nIt should also help by not blocking qdisc fast paths for too long.\nWorst case (65536 flows) would need 31 jiffies for a complete scan.\n\nRelevant extract from syzbot report:\n\nrcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.\nrcu: blocking rcu_node structures (internal RCU debug):\nSending NMI from CPU 1 to CPUs 0:\nNMI backtrace for cpu 0\nCPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023\nRIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]\nRIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236\nCode: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 \u003ca9\u003e 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b\nRSP: 0018:ffffc90000007bb8 EFLAGS: 00000206\nRAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0\nRDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001\nRBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178\nR13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\nFS:  0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \u003cNMI\u003e\n \u003c/NMI\u003e\n \u003cIRQ\u003e\n pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415\n fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387\n call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700"
    }
  ],
  "id": "CVE-2023-53727",
  "lastModified": "2025-10-22T21:12:48.953",
  "metrics": {},
  "published": "2025-10-22T14:15:47.977",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8c21ab1bae945686c602c5bfa4e3f3352c2452c5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/94d527c3759d76c29220758362f622954612bea7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/973a4c302d7f3804098ff9824d9f56926901f293"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e093000e7d13569c9cb07d7500acd5142c3c43cb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f39b49077abec4c9c3a4c2966532004851c51006"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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