CVE-2025-21673

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double free of TCP_Server_Info::hostname When shutting down the server in cifs_put_tcp_session(), cifsd thread might be reconnecting to multiple DFS targets before it realizes it should exit the loop, so @server->hostname can't be freed as long as cifsd thread isn't done. Otherwise the following can happen: RIP: 0010:__slab_free+0x223/0x3c0 Code: 5e 41 5f c3 cc cc cc cc 4c 89 de 4c 89 cf 44 89 44 24 08 4c 89 1c 24 e8 fb cf 8e 00 44 8b 44 24 08 4c 8b 1c 24 e9 5f fe ff ff <0f> 0b 41 f7 45 08 00 0d 21 00 0f 85 2d ff ff ff e9 1f ff ff ff 80 RSP: 0018:ffffb26180dbfd08 EFLAGS: 00010246 RAX: ffff8ea34728e510 RBX: ffff8ea34728e500 RCX: 0000000000800068 RDX: 0000000000800068 RSI: 0000000000000000 RDI: ffff8ea340042400 RBP: ffffe112041ca380 R08: 0000000000000001 R09: 0000000000000000 R10: 6170732e31303000 R11: 70726f632e786563 R12: ffff8ea34728e500 R13: ffff8ea340042400 R14: ffff8ea34728e500 R15: 0000000000800068 FS: 0000000000000000(0000) GS:ffff8ea66fd80000(0000) 000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc25376080 CR3: 000000012a2ba001 CR4: PKRU: 55555554 Call Trace: <TASK> ? show_trace_log_lvl+0x1c4/0x2df ? show_trace_log_lvl+0x1c4/0x2df ? __reconnect_target_unlocked+0x3e/0x160 [cifs] ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0xce/0x120 ? __slab_free+0x223/0x3c0 ? do_error_trap+0x65/0x80 ? __slab_free+0x223/0x3c0 ? exc_invalid_op+0x4e/0x70 ? __slab_free+0x223/0x3c0 ? asm_exc_invalid_op+0x16/0x20 ? __slab_free+0x223/0x3c0 ? extract_hostname+0x5c/0xa0 [cifs] ? extract_hostname+0x5c/0xa0 [cifs] ? __kmalloc+0x4b/0x140 __reconnect_target_unlocked+0x3e/0x160 [cifs] reconnect_dfs_server+0x145/0x430 [cifs] cifs_handle_standard+0x1ad/0x1d0 [cifs] cifs_demultiplex_thread+0x592/0x730 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0xdd/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 </TASK>

Severity

MEDIUM

CVSS score

5.5 (v3.1)

Vulnerability status

Modified

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2025-01-31 12:15:28.463000

Last modified

2026-10-30 13:17:51.270000

View original CVE JSON

{
  "id": "CVE-2025-21673",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-01-31T12:15:28.463",
  "lastModified": "2026-10-30T13:17:51.270",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix double free of TCP_Server_Info::hostname\n\nWhen shutting down the server in cifs_put_tcp_session(), cifsd thread\nmight be reconnecting to multiple DFS targets before it realizes it\nshould exit the loop, so @server->hostname can't be freed as long as\ncifsd thread isn't done.  Otherwise the following can happen:\n\n  RIP: 0010:__slab_free+0x223/0x3c0\n  Code: 5e 41 5f c3 cc cc cc cc 4c 89 de 4c 89 cf 44 89 44 24 08 4c 89\n  1c 24 e8 fb cf 8e 00 44 8b 44 24 08 4c 8b 1c 24 e9 5f fe ff ff <0f>\n  0b 41 f7 45 08 00 0d 21 00 0f 85 2d ff ff ff e9 1f ff ff ff 80\n  RSP: 0018:ffffb26180dbfd08 EFLAGS: 00010246\n  RAX: ffff8ea34728e510 RBX: ffff8ea34728e500 RCX: 0000000000800068\n  RDX: 0000000000800068 RSI: 0000000000000000 RDI: ffff8ea340042400\n  RBP: ffffe112041ca380 R08: 0000000000000001 R09: 0000000000000000\n  R10: 6170732e31303000 R11: 70726f632e786563 R12: ffff8ea34728e500\n  R13: ffff8ea340042400 R14: ffff8ea34728e500 R15: 0000000000800068\n  FS: 0000000000000000(0000) GS:ffff8ea66fd80000(0000)\n  000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007ffc25376080 CR3: 000000012a2ba001 CR4:\n  PKRU: 55555554\n  Call Trace:\n   <TASK>\n   ? show_trace_log_lvl+0x1c4/0x2df\n   ? show_trace_log_lvl+0x1c4/0x2df\n   ? __reconnect_target_unlocked+0x3e/0x160 [cifs]\n   ? __die_body.cold+0x8/0xd\n   ? die+0x2b/0x50\n   ? do_trap+0xce/0x120\n   ? __slab_free+0x223/0x3c0\n   ? do_error_trap+0x65/0x80\n   ? __slab_free+0x223/0x3c0\n   ? exc_invalid_op+0x4e/0x70\n   ? __slab_free+0x223/0x3c0\n   ? asm_exc_invalid_op+0x16/0x20\n   ? __slab_free+0x223/0x3c0\n   ? extract_hostname+0x5c/0xa0 [cifs]\n   ? extract_hostname+0x5c/0xa0 [cifs]\n   ? __kmalloc+0x4b/0x140\n   __reconnect_target_unlocked+0x3e/0x160 [cifs]\n   reconnect_dfs_server+0x145/0x430 [cifs]\n   cifs_handle_standard+0x1ad/0x1d0 [cifs]\n   cifs_demultiplex_thread+0x592/0x730 [cifs]\n   ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]\n   kthread+0xdd/0x100\n   ? __pfx_kthread+0x10/0x10\n   ret_from_fork+0x29/0x50\n   </TASK>"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: smb: cliente: se corrige la doble liberación de TCP_Server_Info::hostname Al apagar el servidor en cifs_put_tcp_session(), el hilo cifsd podría estar reconectándose a múltiples objetivos DFS antes de darse cuenta de que debería salir del bucle, por lo que @server-&gt;hostname no se puede liberar mientras el hilo cifsd no haya terminado. De lo contrario, puede ocurrir lo siguiente: RIP: 0010:__slab_free+0x223/0x3c0 Code: 5e 41 5f c3 cc cc cc cc 4c 89 de 4c 89 cf 44 89 44 24 08 4c 89 1c 24 e8 fb cf 8e 00 44 8b 44 24 08 4c 8b 1c 24 e9 5f fe ff ff &lt;0f&gt; 0b 41 f7 45 08 00 0d 21 00 0f 85 2d ff ff ff e9 1f ff ff ff 80 RSP: 0018:ffffb26180dbfd08 EFLAGS: 00010246 RAX: ffff8ea34728e510 RBX: ffff8ea34728e500 RCX: 0000000000800068 RDX: 0000000000800068 RSI: 0000000000000000 RDI: ffff8ea340042400 RBP: ffffe112041ca380 R08: 0000000000000001 R09: 0000000000000000 R10: 6170732e31303000 R11: 70726f632e786563 R12: ffff8ea34728e500 R13: ffff8ea340042400 R14: ffff8ea34728e500 R15: 0000000000800068 FS: 0000000000000000(0000) GS:ffff8ea66fd80000(0000) 000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc25376080 CR3: 000000012a2ba001 CR4: PKRU: 55555554 Call Trace:  ? show_trace_log_lvl+0x1c4/0x2df ? show_trace_log_lvl+0x1c4/0x2df ? __reconnect_target_unlocked+0x3e/0x160 [cifs] ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0xce/0x120 ? __slab_free+0x223/0x3c0 ? do_error_trap+0x65/0x80 ? __slab_free+0x223/0x3c0 ? exc_invalid_op+0x4e/0x70 ? __slab_free+0x223/0x3c0 ? asm_exc_invalid_op+0x16/0x20 ? __slab_free+0x223/0x3c0 ? extract_hostname+0x5c/0xa0 [cifs] ? extract_hostname+0x5c/0xa0 [cifs] ? __kmalloc+0x4b/0x140 __reconnect_target_unlocked+0x3e/0x160 [cifs] reconnect_dfs_server+0x145/0x430 [cifs] cifs_handle_standard+0x1ad/0x1d0 [cifs] cifs_demultiplex_thread+0x592/0x730 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0xdd/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 "
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/client/connect.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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        },
        {
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          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
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              "status": "unaffected"
            },
            {
              "version": "6.6.74",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.11",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.13",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
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            },
            {
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          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
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  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
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}