Vulnerability-Lookup

FKIE_CVE-2025-71126

Vulnerability from fkie_nvd - Published: 2026-01-14 15:16 - Updated: 2026-03-25 18:50

Severity ?

5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: mptcp: avoid deadlock on fallback while reinjecting Jakub reported an MPTCP deadlock at fallback time: WARNING: possible recursive locking detected 6.18.0-rc7-virtme #1 Not tainted -------------------------------------------- mptcp_connect/20858 is trying to acquire lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280 but task is already holding lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&msk->fallback_lock); lock(&msk->fallback_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mptcp_connect/20858: #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0 #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0 #2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 stack backtrace: CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full) Hardware name: Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_deadlock_bug.cold+0xc0/0xcd validate_chain+0x2ff/0x5f0 __lock_acquire+0x34c/0x740 lock_acquire.part.0+0xbc/0x260 _raw_spin_lock_bh+0x38/0x50 __mptcp_try_fallback+0xd8/0x280 mptcp_sendmsg_frag+0x16c2/0x3050 __mptcp_retrans+0x421/0xaa0 mptcp_release_cb+0x5aa/0xa70 release_sock+0xab/0x1d0 mptcp_sendmsg+0xd5b/0x1bc0 sock_write_iter+0x281/0x4d0 new_sync_write+0x3c5/0x6f0 vfs_write+0x65e/0xbb0 ksys_write+0x17e/0x200 do_syscall_64+0xbb/0xfd0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fa5627cbc5e Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005 RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920 R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c The packet scheduler could attempt a reinjection after receiving an MP_FAIL and before the infinite map has been transmitted, causing a deadlock since MPTCP needs to do the reinjection atomically from WRT fallback. Address the issue explicitly avoiding the reinjection in the critical scenario. Note that this is the only fallback critical section that could potentially send packets and hit the double-lock.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0107442e82c0f8d6010e07e6030741c59c520d6e	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0ca9fb4335e726dab4f23b3bfe87271d8f005f41	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/252892d5a6a2f163ce18f32716e46fa4da7d4e79	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/50f47c02be419bf0a3ae94c118addf67beef359f	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ffb8c27b0539dd90262d1021488e7817fae57c42	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	6.16
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19
linux	linux_kernel	6.19

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: avoid deadlock on fallback while reinjecting\n\nJakub reported an MPTCP deadlock at fallback time:\n\n WARNING: possible recursive locking detected\n 6.18.0-rc7-virtme #1 Not tainted\n --------------------------------------------\n mptcp_connect/20858 is trying to acquire lock:\n ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280\n\n but task is already holding lock:\n ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n other info that might help us debug this:\n  Possible unsafe locking scenario:\n\n        CPU0\n        ----\n   lock(\u0026msk-\u003efallback_lock);\n   lock(\u0026msk-\u003efallback_lock);\n\n  *** DEADLOCK ***\n\n  May be due to missing lock nesting notation\n\n 3 locks held by mptcp_connect/20858:\n  #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0\n  #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0\n  #2: ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n stack backtrace:\n CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full)\n Hardware name: Bochs, BIOS Bochs 01/01/2011\n Call Trace:\n  \u003cTASK\u003e\n  dump_stack_lvl+0x6f/0xa0\n  print_deadlock_bug.cold+0xc0/0xcd\n  validate_chain+0x2ff/0x5f0\n  __lock_acquire+0x34c/0x740\n  lock_acquire.part.0+0xbc/0x260\n  _raw_spin_lock_bh+0x38/0x50\n  __mptcp_try_fallback+0xd8/0x280\n  mptcp_sendmsg_frag+0x16c2/0x3050\n  __mptcp_retrans+0x421/0xaa0\n  mptcp_release_cb+0x5aa/0xa70\n  release_sock+0xab/0x1d0\n  mptcp_sendmsg+0xd5b/0x1bc0\n  sock_write_iter+0x281/0x4d0\n  new_sync_write+0x3c5/0x6f0\n  vfs_write+0x65e/0xbb0\n  ksys_write+0x17e/0x200\n  do_syscall_64+0xbb/0xfd0\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7fa5627cbc5e\n Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 \u003cc9\u003e c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa\n RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001\n RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e\n RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005\n RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920\n R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c\n\nThe packet scheduler could attempt a reinjection after receiving an\nMP_FAIL and before the infinite map has been transmitted, causing a\ndeadlock since MPTCP needs to do the reinjection atomically from WRT\nfallback.\n\nAddress the issue explicitly avoiding the reinjection in the critical\nscenario. Note that this is the only fallback critical section that\ncould potentially send packets and hit the double-lock."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmptcp: evitar interbloqueo en el fallback mientras se reinjecta\n\nJakub inform\u00f3 un interbloqueo MPTCP en el momento del fallback:\n\n WARNING: possible recursive locking detected\n 6.18.0-rc7-virtme #1 Not tainted\n --------------------------------------------\n mptcp_connect/20858 is trying to acquire lock:\n ff1100001da18b60 (\u0026amp;msk-\u0026gt;fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280\n\n but task is already holding lock:\n ff1100001da18b60 (\u0026amp;msk-\u0026gt;fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n other info that might help us debug this:\n  Possible unsafe locking scenario:\n\n        CPU0\n        ----\n   lock(\u0026amp;msk-\u0026gt;fallback_lock);\n   lock(\u0026amp;msk-\u0026gt;fallback_lock);\n\n  * DEADLOCK *\n\n  May be due to missing lock nesting notation\n\n 3 locks held by mptcp_connect/20858:\n  #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0\n  #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0\n  #2: ff1100001da18b60 (\u0026amp;msk-\u0026gt;fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n stack backtrace:\n CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full)\n Hardware name: Bochs, BIOS Bochs 01/01/2011\n Call Trace:\n  \n  dump_stack_lvl+0x6f/0xa0\n  print_deadlock_bug.cold+0xc0/0xcd\n  validate_chain+0x2ff/0x5f0\n  __lock_acquire+0x34c/0x740\n  lock_acquire.part.0+0xbc/0x260\n  _raw_spin_lock_bh+0x38/0x50\n  __mptcp_try_fallback+0xd8/0x280\n  mptcp_sendmsg_frag+0x16c2/0x3050\n  __mptcp_retrans+0x421/0xaa0\n  mptcp_release_cb+0x5aa/0xa70\n  release_sock+0xab/0x1d0\n  mptcp_sendmsg+0xd5b/0x1bc0\n  sock_write_iter+0x281/0x4d0\n  new_sync_write+0x3c5/0x6f0\n  vfs_write+0x65e/0xbb0\n  ksys_write+0x17e/0x200\n  do_syscall_64+0xbb/0xfd0\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7fa5627cbc5e\n Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05  c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa\n RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001\n RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e\n RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005\n RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920\n R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c\n\nEl planificador de paquetes podr\u00eda intentar una reinyecci\u00f3n despu\u00e9s de recibir un MP_FAIL y antes de que se haya transmitido el mapa infinito, causando un interbloqueo ya que MPTCP necesita realizar la reinyecci\u00f3n at\u00f3micamente con respecto al fallback.\n\nAbordar el problema evitando expl\u00edcitamente la reinyecci\u00f3n en el escenario cr\u00edtico. Tenga en cuenta que esta es la \u00fanica secci\u00f3n cr\u00edtica de fallback que podr\u00eda potencialmente enviar paquetes y alcanzar el doble bloqueo."
    }
  ],
  "id": "CVE-2025-71126",
  "lastModified": "2026-03-25T18:50:29.743",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-01-14T15:16:02.317",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/0107442e82c0f8d6010e07e6030741c59c520d6e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/0ca9fb4335e726dab4f23b3bfe87271d8f005f41"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/252892d5a6a2f163ce18f32716e46fa4da7d4e79"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/50f47c02be419bf0a3ae94c118addf67beef359f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/ffb8c27b0539dd90262d1021488e7817fae57c42"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-667"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2025-71126 (GCVE-0-2025-71126)

Vulnerability from cvelistv5 – Published: 2026-01-14 15:06 – Updated: 2026-02-09 08:35

Title

mptcp: avoid deadlock on fallback while reinjecting

Summary

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/0107442e82c0f8d60…
	https://git.kernel.org/stable/c/252892d5a6a2f163c…
	https://git.kernel.org/stable/c/0ca9fb4335e726dab…
	https://git.kernel.org/stable/c/50f47c02be419bf0a…
	https://git.kernel.org/stable/c/ffb8c27b0539dd902…

Impacted products

Vendor

Product

Version

Linux

Affected: 5586518bec27666c747cd52aabb62d485686d0bf , < 0107442e82c0f8d6010e07e6030741c59c520d6e (git)
Affected: 75a4c9ab8a7af0d76b31ccd1188ed178c38b35d2 , < 252892d5a6a2f163ce18f32716e46fa4da7d4e79 (git)
Affected: 54999dea879fecb761225e28f274b40662918c30 , < 0ca9fb4335e726dab4f23b3bfe87271d8f005f41 (git)
Affected: f8a1d9b18c5efc76784f5a326e905f641f839894 , < 50f47c02be419bf0a3ae94c118addf67beef359f (git)
Affected: f8a1d9b18c5efc76784f5a326e905f641f839894 , < ffb8c27b0539dd90262d1021488e7817fae57c42 (git)
Affected: 1d82a8fe6ee4afdc92f4e8808c9dad2a6095bbc5 (git)

Linux

Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.1.160 , ≤ 6.1.* (semver)
Unaffected: 6.6.120 , ≤ 6.6.* (semver)
Unaffected: 6.12.64 , ≤ 6.12.* (semver)
Unaffected: 6.18.3 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/protocol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "0107442e82c0f8d6010e07e6030741c59c520d6e",
              "status": "affected",
              "version": "5586518bec27666c747cd52aabb62d485686d0bf",
              "versionType": "git"
            },
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              "lessThan": "252892d5a6a2f163ce18f32716e46fa4da7d4e79",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "0ca9fb4335e726dab4f23b3bfe87271d8f005f41",
              "status": "affected",
              "version": "54999dea879fecb761225e28f274b40662918c30",
              "versionType": "git"
            },
            {
              "lessThan": "50f47c02be419bf0a3ae94c118addf67beef359f",
              "status": "affected",
              "version": "f8a1d9b18c5efc76784f5a326e905f641f839894",
              "versionType": "git"
            },
            {
              "lessThan": "ffb8c27b0539dd90262d1021488e7817fae57c42",
              "status": "affected",
              "version": "f8a1d9b18c5efc76784f5a326e905f641f839894",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1d82a8fe6ee4afdc92f4e8808c9dad2a6095bbc5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/mptcp/protocol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.120",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.64",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.160",
                  "versionStartIncluding": "6.1.149",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.120",
                  "versionStartIncluding": "6.6.101",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.64",
                  "versionStartIncluding": "6.12.40",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.3",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.15.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: avoid deadlock on fallback while reinjecting\n\nJakub reported an MPTCP deadlock at fallback time:\n\n WARNING: possible recursive locking detected\n 6.18.0-rc7-virtme #1 Not tainted\n --------------------------------------------\n mptcp_connect/20858 is trying to acquire lock:\n ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280\n\n but task is already holding lock:\n ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n other info that might help us debug this:\n  Possible unsafe locking scenario:\n\n        CPU0\n        ----\n   lock(\u0026msk-\u003efallback_lock);\n   lock(\u0026msk-\u003efallback_lock);\n\n  *** DEADLOCK ***\n\n  May be due to missing lock nesting notation\n\n 3 locks held by mptcp_connect/20858:\n  #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0\n  #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0\n  #2: ff1100001da18b60 (\u0026msk-\u003efallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0\n\n stack backtrace:\n CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full)\n Hardware name: Bochs, BIOS Bochs 01/01/2011\n Call Trace:\n  \u003cTASK\u003e\n  dump_stack_lvl+0x6f/0xa0\n  print_deadlock_bug.cold+0xc0/0xcd\n  validate_chain+0x2ff/0x5f0\n  __lock_acquire+0x34c/0x740\n  lock_acquire.part.0+0xbc/0x260\n  _raw_spin_lock_bh+0x38/0x50\n  __mptcp_try_fallback+0xd8/0x280\n  mptcp_sendmsg_frag+0x16c2/0x3050\n  __mptcp_retrans+0x421/0xaa0\n  mptcp_release_cb+0x5aa/0xa70\n  release_sock+0xab/0x1d0\n  mptcp_sendmsg+0xd5b/0x1bc0\n  sock_write_iter+0x281/0x4d0\n  new_sync_write+0x3c5/0x6f0\n  vfs_write+0x65e/0xbb0\n  ksys_write+0x17e/0x200\n  do_syscall_64+0xbb/0xfd0\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7fa5627cbc5e\n Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 \u003cc9\u003e c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa\n RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001\n RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e\n RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005\n RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920\n R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c\n\nThe packet scheduler could attempt a reinjection after receiving an\nMP_FAIL and before the infinite map has been transmitted, causing a\ndeadlock since MPTCP needs to do the reinjection atomically from WRT\nfallback.\n\nAddress the issue explicitly avoiding the reinjection in the critical\nscenario. Note that this is the only fallback critical section that\ncould potentially send packets and hit the double-lock."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-09T08:35:21.899Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0107442e82c0f8d6010e07e6030741c59c520d6e"
        },
        {
          "url": "https://git.kernel.org/stable/c/252892d5a6a2f163ce18f32716e46fa4da7d4e79"
        },
        {
          "url": "https://git.kernel.org/stable/c/0ca9fb4335e726dab4f23b3bfe87271d8f005f41"
        },
        {
          "url": "https://git.kernel.org/stable/c/50f47c02be419bf0a3ae94c118addf67beef359f"
        },
        {
          "url": "https://git.kernel.org/stable/c/ffb8c27b0539dd90262d1021488e7817fae57c42"
        }
      ],
      "title": "mptcp: avoid deadlock on fallback while reinjecting",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-71126",
    "datePublished": "2026-01-14T15:06:11.417Z",
    "dateReserved": "2026-01-13T15:30:19.655Z",
    "dateUpdated": "2026-02-09T08:35:21.899Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2025-71126

CVE-2025-71126 (GCVE-0-2025-71126)

Tags

Sightings

Nomenclature