CWE-476
AllowedNULL Pointer Dereference
Abstraction: Base · Status: Stable
The product dereferences a pointer that it expects to be valid but is NULL.
6325 vulnerabilities reference this CWE, most recent first.
GHSA-HP5R-FRGX-32V8
Vulnerability from github – Published: 2025-03-27 15:31 – Updated: 2026-06-26 00:31A flaw was found in gnuplot. The plot3d_points() function may lead to a segmentation fault and cause a system crash.
{
"affected": [],
"aliases": [
"CVE-2025-31176"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-03-27T15:16:03Z",
"severity": "MODERATE"
},
"details": "A flaw was found in gnuplot. The plot3d_points() function may lead to a segmentation fault and cause a system crash.",
"id": "GHSA-hp5r-frgx-32v8",
"modified": "2026-06-26T00:31:58Z",
"published": "2025-03-27T15:31:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-31176"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2025-31176"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2355343"
},
{
"type": "WEB",
"url": "https://sourceforge.net/p/gnuplot/bugs/2776"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HP67-RVGQ-RWRP
Vulnerability from github – Published: 2025-03-13 21:31 – Updated: 2025-03-13 21:31In the Linux kernel, the following vulnerability has been resolved:
net: dsa: felix: fix possible NULL pointer dereference
As the possible failure of the allocation, kzalloc() may return NULL pointer. Therefore, it should be better to check the 'sgi' in order to prevent the dereference of NULL pointer.
{
"affected": [],
"aliases": [
"CVE-2022-49141"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-26T07:00:51Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: felix: fix possible NULL pointer dereference\n\nAs the possible failure of the allocation, kzalloc() may return NULL\npointer.\nTherefore, it should be better to check the \u0027sgi\u0027 in order to prevent\nthe dereference of NULL pointer.",
"id": "GHSA-hp67-rvgq-rwrp",
"modified": "2025-03-13T21:31:18Z",
"published": "2025-03-13T21:31:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49141"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/866b7a278cdb51eb158cd8513bc7438fc857804a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b7ff8b5e75d4e91ec8c62d621aac8dfb84c57aa9"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HP7V-34MP-F79P
Vulnerability from github – Published: 2024-01-25 09:30 – Updated: 2026-05-12 12:31NULL Pointer Dereference vulnerability in Linux Linux kernel kernel on Linux, x86, ARM (net, bluetooth modules) allows Overflow Buffers. This vulnerability is associated with program files /net/bluetooth/rfcomm/core.C.
This issue affects Linux kernel: v2.6.12-rc2.
{
"affected": [],
"aliases": [
"CVE-2024-22099"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-25T07:15:08Z",
"severity": "MODERATE"
},
"details": "NULL Pointer Dereference vulnerability in Linux Linux kernel kernel on Linux, x86, ARM (net, bluetooth modules) allows Overflow Buffers. This vulnerability is associated with program files /net/bluetooth/rfcomm/core.C.\n\nThis issue affects Linux kernel: v2.6.12-rc2.",
"id": "GHSA-hp7v-34mp-f79p",
"modified": "2026-05-12T12:31:34Z",
"published": "2024-01-25T09:30:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-22099"
},
{
"type": "WEB",
"url": "https://bugzilla.openanolis.cn/show_bug.cgi?id=7956"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IVVYSTEVMPYGF6GDSOD44MUXZXAZHOHB"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KSXNF4RLEFLH35BFUQGYXRRVHHUIVBAE"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HP7W-J9MX-8VPJ
Vulnerability from github – Published: 2025-11-24 15:30 – Updated: 2025-11-24 21:30Null pointer dereference in add_ca_certs() in Cesanta Mongoose before 7.2 allows remote attackers to cause a denial of service via TLS initialization where SSL_CTX_get_cert_store() returns NULL.
{
"affected": [],
"aliases": [
"CVE-2025-65502"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-24T14:15:48Z",
"severity": "MODERATE"
},
"details": "Null pointer dereference in add_ca_certs() in Cesanta Mongoose before 7.2 allows remote attackers to cause a denial of service via TLS initialization where SSL_CTX_get_cert_store() returns NULL.",
"id": "GHSA-hp7w-j9mx-8vpj",
"modified": "2025-11-24T21:30:58Z",
"published": "2025-11-24T15:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-65502"
},
{
"type": "WEB",
"url": "https://github.com/cesanta/mongoose/issues/3306"
},
{
"type": "WEB",
"url": "https://github.com/cesanta/mongoose/pull/3307"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-HP8R-5243-X9F3
Vulnerability from github – Published: 2022-05-13 01:28 – Updated: 2025-04-20 03:40libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_get_path function in util.c.
{
"affected": [],
"aliases": [
"CVE-2017-11125"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-07-10T03:29:00Z",
"severity": "CRITICAL"
},
"details": "libxar.so in xar 1.6.1 has a NULL pointer dereference in the xar_get_path function in util.c.",
"id": "GHSA-hp8r-5243-x9f3",
"modified": "2025-04-20T03:40:29Z",
"published": "2022-05-13T01:28:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-11125"
},
{
"type": "WEB",
"url": "https://blogs.gentoo.org/ago/2017/06/28/xar-null-pointer-dereference-in-xar_get_path-util-c"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2S2KRIILUKBJHXDNYJQQX74TFUQRG5ND"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YV6RF6VWM7AFYFTTS7VY5TNH26QUEEFC"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2S2KRIILUKBJHXDNYJQQX74TFUQRG5ND"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YV6RF6VWM7AFYFTTS7VY5TNH26QUEEFC"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HPC7-GCQM-58FV
Vulnerability from github – Published: 2026-01-27 18:32 – Updated: 2026-03-20 15:31Issue summary: PBMAC1 parameters in PKCS#12 files are missing validation which can trigger a stack-based buffer overflow, invalid pointer or NULL pointer dereference during MAC verification.
Impact summary: The stack buffer overflow or NULL pointer dereference may cause a crash leading to Denial of Service for an application that parses untrusted PKCS#12 files. The buffer overflow may also potentially enable code execution depending on platform mitigations.
When verifying a PKCS#12 file that uses PBMAC1 for the MAC, the PBKDF2 salt and keylength parameters from the file are used without validation. If the value of keylength exceeds the size of the fixed stack buffer used for the derived key (64 bytes), the key derivation will overflow the buffer. The overflow length is attacker-controlled. Also, if the salt parameter is not an OCTET STRING type this can lead to invalid or NULL pointer dereference.
Exploiting this issue requires a user or application to process a maliciously crafted PKCS#12 file. It is uncommon to accept untrusted PKCS#12 files in applications as they are usually used to store private keys which are trusted by definition. For this reason the issue was assessed as Moderate severity.
The FIPS modules in 3.6, 3.5 and 3.4 are not affected by this issue, as PKCS#12 processing is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5 and 3.4 are vulnerable to this issue.
OpenSSL 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue as they do not support PBMAC1 in PKCS#12.
{
"affected": [],
"aliases": [
"CVE-2025-11187"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-27T16:16:14Z",
"severity": "MODERATE"
},
"details": "Issue summary: PBMAC1 parameters in PKCS#12 files are missing validation\nwhich can trigger a stack-based buffer overflow, invalid pointer or NULL\npointer dereference during MAC verification.\n\nImpact summary: The stack buffer overflow or NULL pointer dereference may\ncause a crash leading to Denial of Service for an application that parses\nuntrusted PKCS#12 files. The buffer overflow may also potentially enable\ncode execution depending on platform mitigations.\n\nWhen verifying a PKCS#12 file that uses PBMAC1 for the MAC, the PBKDF2\nsalt and keylength parameters from the file are used without validation.\nIf the value of keylength exceeds the size of the fixed stack buffer used\nfor the derived key (64 bytes), the key derivation will overflow the buffer.\nThe overflow length is attacker-controlled. Also, if the salt parameter is\nnot an OCTET STRING type this can lead to invalid or NULL pointer\ndereference.\n\nExploiting this issue requires a user or application to process\na maliciously crafted PKCS#12 file. It is uncommon to accept untrusted\nPKCS#12 files in applications as they are usually used to store private\nkeys which are trusted by definition. For this reason the issue was assessed\nas Moderate severity.\n\nThe FIPS modules in 3.6, 3.5 and 3.4 are not affected by this issue, as\nPKCS#12 processing is outside the OpenSSL FIPS module boundary.\n\nOpenSSL 3.6, 3.5 and 3.4 are vulnerable to this issue.\n\nOpenSSL 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue as they do\nnot support PBMAC1 in PKCS#12.",
"id": "GHSA-hpc7-gcqm-58fv",
"modified": "2026-03-20T15:31:04Z",
"published": "2026-01-27T18:32:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-11187"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/205e3a55e16e4bd08c12fdbd3416ab829c0f6206"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/8caf359d6e46fb413e8f5f0df765d2e8a51df4e8"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/e1079bc17ed93ff16f6b86f33a2fe3336e78817e"
},
{
"type": "WEB",
"url": "https://github.com/metadust/CVE-2025-11187"
},
{
"type": "WEB",
"url": "https://openssl-library.org/news/secadv/20260127.txt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HPF6-962W-3G93
Vulnerability from github – Published: 2025-01-22 00:33 – Updated: 2025-01-23 18:31A Null pointer dereference vulnerability in the Mobile Management Entity (MME) in Magma <= 1.8.0 (fixed in v1.9 commit 08472ba98b8321f802e95f5622fa90fec2dea486) allows network-adjacent attackers to crash the MME via an S1AP E-RAB Release Response packet missing an expected MME_UE_S1AP_ID field.
{
"affected": [],
"aliases": [
"CVE-2023-37026"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-01-21T23:15:09Z",
"severity": "MODERATE"
},
"details": "A Null pointer dereference vulnerability in the Mobile Management Entity (MME) in Magma \u003c= 1.8.0 (fixed in v1.9 commit 08472ba98b8321f802e95f5622fa90fec2dea486) allows network-adjacent attackers to crash the MME via an S1AP `E-RAB Release Response` packet missing an expected `MME_UE_S1AP_ID` field.",
"id": "GHSA-hpf6-962w-3g93",
"modified": "2025-01-23T18:31:18Z",
"published": "2025-01-22T00:33:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-37026"
},
{
"type": "WEB",
"url": "https://cellularsecurity.org/ransacked"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HPJC-M442-8HRM
Vulnerability from github – Published: 2025-10-04 09:30 – Updated: 2026-01-23 21:30In the Linux kernel, the following vulnerability has been resolved:
drm: bridge: anx7625: Fix NULL pointer dereference with early IRQ
If the interrupt occurs before resource initialization is complete, the interrupt handler/worker may access uninitialized data such as the I2C tcpc_client device, potentially leading to NULL pointer dereference.
{
"affected": [],
"aliases": [
"CVE-2025-39934"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-04T08:15:46Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm: bridge: anx7625: Fix NULL pointer dereference with early IRQ\n\nIf the interrupt occurs before resource initialization is complete, the\ninterrupt handler/worker may access uninitialized data such as the I2C\ntcpc_client device, potentially leading to NULL pointer dereference.",
"id": "GHSA-hpjc-m442-8hrm",
"modified": "2026-01-23T21:30:36Z",
"published": "2025-10-04T09:30:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39934"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0da73f7827691a5e2265b110d5fe12f29535ec92"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/15a77e1ab0a994d69b471c76b8d01117128dda26"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1a7ea294d57fb61485d11b3f2241d631d73025cb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/51a501e990a353a4f15da6bab295b28e5d118f64"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a10f910c77f280327b481e77eab909934ec508f0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f9a089d0a6d537d0f2061c8a37a7de535ce0310e"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HPP4-8VC7-9FH4
Vulnerability from github – Published: 2024-05-19 09:34 – Updated: 2026-05-12 12:31In the Linux kernel, the following vulnerability has been resolved:
net/rds: fix possible cp null dereference
cp might be null, calling cp->cp_conn would produce null dereference
[Simon Horman adds:]
Analysis:
-
cp is a parameter of __rds_rdma_map and is not reassigned.
-
The following call-sites pass a NULL cp argument to __rds_rdma_map()
-
rds_get_mr()
-
rds_get_mr_for_dest
-
Prior to the code above, the following assumes that cp may be NULL (which is indicative, but could itself be unnecessary)
trans_private = rs->rs_transport->get_mr( sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL, args->vec.addr, args->vec.bytes, need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);
-
The code modified by this patch is guarded by IS_ERR(trans_private), where trans_private is assigned as per the previous point in this analysis.
The only implementation of get_mr that I could locate is rds_ib_get_mr() which can return an ERR_PTR if the conn (4th) argument is NULL.
- ret is set to PTR_ERR(trans_private). rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL. Thus ret may be -ENODEV in which case the code in question will execute.
Conclusion: * cp may be NULL at the point where this patch adds a check; this patch does seem to address a possible bug
{
"affected": [],
"aliases": [
"CVE-2024-35902"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-19T09:15:11Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: fix possible cp null dereference\n\ncp might be null, calling cp-\u003ecp_conn would produce null dereference\n\n[Simon Horman adds:]\n\nAnalysis:\n\n* cp is a parameter of __rds_rdma_map and is not reassigned.\n\n* The following call-sites pass a NULL cp argument to __rds_rdma_map()\n\n - rds_get_mr()\n - rds_get_mr_for_dest\n\n* Prior to the code above, the following assumes that cp may be NULL\n (which is indicative, but could itself be unnecessary)\n\n\ttrans_private = rs-\u003ers_transport-\u003eget_mr(\n\t\tsg, nents, rs, \u0026mr-\u003er_key, cp ? cp-\u003ecp_conn : NULL,\n\t\targs-\u003evec.addr, args-\u003evec.bytes,\n\t\tneed_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);\n\n* The code modified by this patch is guarded by IS_ERR(trans_private),\n where trans_private is assigned as per the previous point in this analysis.\n\n The only implementation of get_mr that I could locate is rds_ib_get_mr()\n which can return an ERR_PTR if the conn (4th) argument is NULL.\n\n* ret is set to PTR_ERR(trans_private).\n rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL.\n Thus ret may be -ENODEV in which case the code in question will execute.\n\nConclusion:\n* cp may be NULL at the point where this patch adds a check;\n this patch does seem to address a possible bug",
"id": "GHSA-hpp4-8vc7-9fh4",
"modified": "2026-05-12T12:31:49Z",
"published": "2024-05-19T09:34:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35902"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/62fc3357e079a07a22465b9b6ef71bb6ea75ee4b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6794090c742008c53b344b35b021d4a3093dc50a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/92309bed3c5fbe2ccd4c45056efd42edbd06162d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bcd46782e2ec3825d10c1552fcb674d491cc09f9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cbaac2e5488ed54833897264a5ffb2a341a9f196"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cfb786b03b03c5ff38882bee38525eb9987e4d14"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d275de8ea7be3a453629fddae41d4156762e814c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d49fac38479bfdaec52b3ea274d290c47a294029"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HQ23-GGCP-MX5X
Vulnerability from github – Published: 2025-09-23 06:30 – Updated: 2025-12-12 21:31In the Linux kernel, the following vulnerability has been resolved:
ceph: always call ceph_shift_unused_folios_left()
The function ceph_process_folio_batch() sets folio_batch entries to NULL, which is an illegal state. Before folio_batch_release() crashes due to this API violation, the function ceph_shift_unused_folios_left() is supposed to remove those NULLs from the array.
However, since commit ce80b76dd327 ("ceph: introduce
ceph_process_folio_batch() method"), this shifting doesn't happen
anymore because the "for" loop got moved to ceph_process_folio_batch(),
and now the i variable that remains in ceph_writepages_start()
doesn't get incremented anymore, making the shifting effectively
unreachable much of the time.
Later, commit 1551ec61dc55 ("ceph: introduce ceph_submit_write()
method") added more preconditions for doing the shift, replacing the
i check (with something that is still just as broken):
-
if ceph_process_folio_batch() fails, shifting never happens
-
if ceph_move_dirty_page_in_page_array() was never called (because ceph_process_folio_batch() has returned early for some of various reasons), shifting never happens
-
if
processed_in_fbatchis zero (because ceph_process_folio_batch() has returned early for some of the reasons mentioned above or because ceph_move_dirty_page_in_page_array() has failed), shifting never happens
Since those two commits, any problem in ceph_process_folio_batch() could crash the kernel, e.g. this way:
BUG: kernel NULL pointer dereference, address: 0000000000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 172 UID: 0 PID: 2342707 Comm: kworker/u778:8 Not tainted 6.15.10-cm4all1-es #714 NONE Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.10 12/08/2023 Workqueue: writeback wb_workfn (flush-ceph-1) RIP: 0010:folios_put_refs+0x85/0x140 Code: 83 c5 01 39 e8 7e 76 48 63 c5 49 8b 5c c4 08 b8 01 00 00 00 4d 85 ed 74 05 41 8b 44 ad 00 48 8b 15 b0 > RSP: 0018:ffffb880af8db778 EFLAGS: 00010207 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000003 RDX: ffffe377cc3b0000 RSI: 0000000000000000 RDI: ffffb880af8db8c0 RBP: 0000000000000000 R08: 000000000000007d R09: 000000000102b86f R10: 0000000000000001 R11: 00000000000000ac R12: ffffb880af8db8c0 R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bd262c97000 FS: 0000000000000000(0000) GS:ffff9c8efc303000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000034 CR3: 0000000160958004 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: ceph_writepages_start+0xeb9/0x1410
The crash can be reproduced easily by changing the
ceph_check_page_before_write() return value to -E2BIG.
(Interestingly, the crash happens only if huge_zero_folio has
already been allocated; without huge_zero_folio,
is_huge_zero_folio(NULL) returns true and folios_put_refs() skips NULL
entries instead of dereferencing them. That makes reproducing the bug
somewhat unreliable. See
https://lore.kernel.org/20250826231626.218675-1-max.kellermann@ionos.com
for a discussion of this detail.)
My suggestion is to move the ceph_shift_unused_folios_left() to right after ceph_process_folio_batch() to ensure it always gets called to fix up the illegal folio_batch state.
{
"affected": [],
"aliases": [
"CVE-2025-39879"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-23T06:15:47Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: always call ceph_shift_unused_folios_left()\n\nThe function ceph_process_folio_batch() sets folio_batch entries to\nNULL, which is an illegal state. Before folio_batch_release() crashes\ndue to this API violation, the function ceph_shift_unused_folios_left()\nis supposed to remove those NULLs from the array.\n\nHowever, since commit ce80b76dd327 (\"ceph: introduce\nceph_process_folio_batch() method\"), this shifting doesn\u0027t happen\nanymore because the \"for\" loop got moved to ceph_process_folio_batch(),\nand now the `i` variable that remains in ceph_writepages_start()\ndoesn\u0027t get incremented anymore, making the shifting effectively\nunreachable much of the time.\n\nLater, commit 1551ec61dc55 (\"ceph: introduce ceph_submit_write()\nmethod\") added more preconditions for doing the shift, replacing the\n`i` check (with something that is still just as broken):\n\n- if ceph_process_folio_batch() fails, shifting never happens\n\n- if ceph_move_dirty_page_in_page_array() was never called (because\n ceph_process_folio_batch() has returned early for some of various\n reasons), shifting never happens\n\n- if `processed_in_fbatch` is zero (because ceph_process_folio_batch()\n has returned early for some of the reasons mentioned above or\n because ceph_move_dirty_page_in_page_array() has failed), shifting\n never happens\n\nSince those two commits, any problem in ceph_process_folio_batch()\ncould crash the kernel, e.g. this way:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000034\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x0002) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0002 [#1] SMP NOPTI\n CPU: 172 UID: 0 PID: 2342707 Comm: kworker/u778:8 Not tainted 6.15.10-cm4all1-es #714 NONE\n Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.10 12/08/2023\n Workqueue: writeback wb_workfn (flush-ceph-1)\n RIP: 0010:folios_put_refs+0x85/0x140\n Code: 83 c5 01 39 e8 7e 76 48 63 c5 49 8b 5c c4 08 b8 01 00 00 00 4d 85 ed 74 05 41 8b 44 ad 00 48 8b 15 b0 \u003e\n RSP: 0018:ffffb880af8db778 EFLAGS: 00010207\n RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000003\n RDX: ffffe377cc3b0000 RSI: 0000000000000000 RDI: ffffb880af8db8c0\n RBP: 0000000000000000 R08: 000000000000007d R09: 000000000102b86f\n R10: 0000000000000001 R11: 00000000000000ac R12: ffffb880af8db8c0\n R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bd262c97000\n FS: 0000000000000000(0000) GS:ffff9c8efc303000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 0000000000000034 CR3: 0000000160958004 CR4: 0000000000770ef0\n PKRU: 55555554\n Call Trace:\n \u003cTASK\u003e\n ceph_writepages_start+0xeb9/0x1410\n\nThe crash can be reproduced easily by changing the\nceph_check_page_before_write() return value to `-E2BIG`.\n\n(Interestingly, the crash happens only if `huge_zero_folio` has\nalready been allocated; without `huge_zero_folio`,\nis_huge_zero_folio(NULL) returns true and folios_put_refs() skips NULL\nentries instead of dereferencing them. That makes reproducing the bug\nsomewhat unreliable. See\nhttps://lore.kernel.org/20250826231626.218675-1-max.kellermann@ionos.com\nfor a discussion of this detail.)\n\nMy suggestion is to move the ceph_shift_unused_folios_left() to right\nafter ceph_process_folio_batch() to ensure it always gets called to\nfix up the illegal folio_batch state.",
"id": "GHSA-hq23-ggcp-mx5x",
"modified": "2025-12-12T21:31:32Z",
"published": "2025-09-23T06:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39879"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/289b6615cf553d98509a9b273195d9936da1cfb2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cce7c15faaac79b532a07ed6ab8332280ad83762"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-56
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished [REF-1484].
Mitigation
Select a programming language that is not susceptible to these issues.
Mitigation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Mitigation
Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
Mitigation
Explicitly initialize all variables and other data stores, either during declaration or just before the first usage.
No CAPEC attack patterns related to this CWE.