GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2025-39765 (GCVE-0-2025-39765)

Vulnerability from cvelistv5 – Published: 2025-09-11 16:56 – Updated: 2026-05-11 21:35
VLAI
Title
ALSA: timer: fix ida_free call while not allocated
Summary
In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: fix ida_free call while not allocated In the snd_utimer_create() function, if the kasprintf() function return NULL, snd_utimer_put_id() will be called, finally use ida_free() to free the unallocated id 0. the syzkaller reported the following information: ------------[ cut here ]------------ ida_free called for id=0 which is not allocated. WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592 Modules linked in: CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014 RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592 Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...) RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5 RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200 RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0 Call Trace: <TASK> snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer] snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer] snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer] __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer] snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer] vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] The utimer->id should be set properly before the kasprintf() function, ensures the snd_utimer_put_id() function will free the allocated id.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 37745918e0e7575bc40f38da93a99b9fa6406224 , < 34327b362ce2849a5eb02f47e800049e7a20a0ba (git)
Affected: 37745918e0e7575bc40f38da93a99b9fa6406224 , < af386b52531d14c4b20f11c452787b1b6dd4eb8d (git)
Affected: 37745918e0e7575bc40f38da93a99b9fa6406224 , < 5003a65790ed66be882d1987cc2ca86af0de3db1 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.12
Unaffected: 0 , < 6.12 (semver)
Unaffected: 6.12.44 , ≤ 6.12.* (semver)
Unaffected: 6.16.4 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "sound/core/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "34327b362ce2849a5eb02f47e800049e7a20a0ba",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            },
            {
              "lessThan": "af386b52531d14c4b20f11c452787b1b6dd4eb8d",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            },
            {
              "lessThan": "5003a65790ed66be882d1987cc2ca86af0de3db1",
              "status": "affected",
              "version": "37745918e0e7575bc40f38da93a99b9fa6406224",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "sound/core/timer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.44",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16.4",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: fix ida_free call while not allocated\n\nIn the snd_utimer_create() function, if the kasprintf() function return\nNULL, snd_utimer_put_id() will be called, finally use ida_free()\nto free the unallocated id 0.\n\nthe syzkaller reported the following information:\n  ------------[ cut here ]------------\n  ida_free called for id=0 which is not allocated.\n  WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592\n  Modules linked in:\n  CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014\n  RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592\n  Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)\n  RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282\n  RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5\n  RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200\n  RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000\n  R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000\n  R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000\n  FS:  00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0\n  Call Trace:\n   \u003cTASK\u003e\n   snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]\n   snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]\n   snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]\n   __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]\n   snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:907 [inline]\n   __se_sys_ioctl fs/ioctl.c:893 [inline]\n   __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n  [...]\n\nThe utimer-\u003eid should be set properly before the kasprintf() function,\nensures the snd_utimer_put_id() function will free the allocated id."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:35:49.504Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/34327b362ce2849a5eb02f47e800049e7a20a0ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/af386b52531d14c4b20f11c452787b1b6dd4eb8d"
        },
        {
          "url": "https://git.kernel.org/stable/c/5003a65790ed66be882d1987cc2ca86af0de3db1"
        }
      ],
      "title": "ALSA: timer: fix ida_free call while not allocated",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-39765",
    "datePublished": "2025-09-11T16:56:20.738Z",
    "dateReserved": "2025-04-16T07:20:57.126Z",
    "dateUpdated": "2026-05-11T21:35:49.504Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-39765",
      "date": "2026-09-16",
      "epss": "0.00154",
      "percentile": "0.04882"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-39765\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-09-11T17:15:40.807\",\"lastModified\":\"2026-06-17T09:18:26.143\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nALSA: timer: fix ida_free call while not allocated\\n\\nIn the snd_utimer_create() function, if the kasprintf() function return\\nNULL, snd_utimer_put_id() will be called, finally use ida_free()\\nto free the unallocated id 0.\\n\\nthe syzkaller reported the following information:\\n  ------------[ cut here ]------------\\n  ida_free called for id=0 which is not allocated.\\n  WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592\\n  Modules linked in:\\n  CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)\\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014\\n  RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592\\n  Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)\\n  RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282\\n  RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5\\n  RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200\\n  RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000\\n  R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000\\n  R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000\\n  FS:  00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000\\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\\n  CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0\\n  Call Trace:\\n   \u003cTASK\u003e\\n   snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]\\n   snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]\\n   snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]\\n   __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]\\n   snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]\\n   vfs_ioctl fs/ioctl.c:51 [inline]\\n   __do_sys_ioctl fs/ioctl.c:907 [inline]\\n   __se_sys_ioctl fs/ioctl.c:893 [inline]\\n   __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893\\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\\n   do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94\\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n  [...]\\n\\nThe utimer-\u003eid should be set properly before the kasprintf() function,\\nensures the snd_utimer_put_id() function will free the allocated id.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"sound/core/timer.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"37745918e0e7575bc40f38da93a99b9fa6406224\",\"lessThan\":\"34327b362ce2849a5eb02f47e800049e7a20a0ba\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"37745918e0e7575bc40f38da93a99b9fa6406224\",\"lessThan\":\"af386b52531d14c4b20f11c452787b1b6dd4eb8d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"37745918e0e7575bc40f38da93a99b9fa6406224\",\"lessThan\":\"5003a65790ed66be882d1987cc2ca86af0de3db1\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"sound/core/timer.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.44\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.16.4\",\"lessThanOrEqual\":\"6.16.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.17\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-476\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.12\",\"versionEndExcluding\":\"6.12.44\",\"matchCriteriaId\":\"14C4B269-8787-47B5-A04C-8BFCE8F9C2D8\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.16.4\",\"matchCriteriaId\":\"AFC28995-B8C3-4B68-8CB6-78E792B6629D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"327D22EF-390B-454C-BD31-2ED23C998A1C\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"C730CD9A-D969-4A8E-9522-162AAF7C0EE9\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/34327b362ce2849a5eb02f47e800049e7a20a0ba\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5003a65790ed66be882d1987cc2ca86af0de3db1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/af386b52531d14c4b20f11c452787b1b6dd4eb8d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-30T01:19:55+00:00",
      "cve": "CVE-2025-39765",
      "id": "CVE-2025-39765",
      "initial_release_date": "2025-09-11T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ALSA: timer: fix ida_free call while not allocated",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39765.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-30T01:51:54Z",
      "cve": "CVE-2025-39765",
      "id": "CVE-2025-39765",
      "initial_release_date": "2025-09-11T23:24:05Z",
      "product_status:first_fixed": "2",
      "product_status:known_affected": "72",
      "product_status:known_not_affected": "473",
      "product_status:recommended": "154",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-39765",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-39765.json",
      "version": "31"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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

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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.