CVE-2024-50002
static_call: Handle module init failure correctly in static_call_del_module()
Published Oct 21, 2024
CVSS 3.1 · 5.5 Medium
EPSS < 1%
KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:
static_call: Handle module init failure correctly in static_call_del_module()
Module insertion invokes static_call_add_module() to initialize the static
calls in a module. static_call_add_module() invokes __static_call_init(),
which allocates a struct static_call_mod to either encapsulate the built-in
static call sites of the associated key into it so further modules can be
added or to append the module to the module chain.
If that allocation fails the function returns with an error code and the
module core invokes static_call_del_module() to clean up eventually added
static_call_mod entries.
This works correctly, when all keys used by the module were converted over
to a module chain before the failure. If not then static_call_del_module()
causes a #GP as it blindly assumes that key::mods points to a valid struct
static_call_mod.
The problem is that key::mods is not a individual struct member of struct
static_call_key, it's part of a union to save space:
union {
/* bit 0: 0 = mods, 1 = sites */
unsigned long type;
struct static_call_mod *mods;
struct static_call_site *sites;
};
key::sites is a pointer to the list of built-in usage sites of the static
call. The type of the pointer is differentiated by bit 0. A mods pointer
has the bit clear, the sites pointer has the bit set.
As static_call_del_module() blidly assumes that the pointer is a valid
static_call_mod type, it fails to check for this failure case and
dereferences the pointer to the list of built-in call sites, which is
obviously bogus.
Cure it by checking whether the key has a sites or a mods pointer.
If it's a sites pointer then the key is not to be touched. As the sites are
walked in the same order as in __static_call_init() the site walk can be
terminated because all subsequent sites have not been touched by the init
code due to the error exit.
If it was converted before the allocation fail, then the inner loop which
searches for a module match will find nothing.
A fail in the second allocation in __static_call_init() is harmless and
does not require special treatment. The first allocation succeeded and
converted the key to a module chain. That first entry has mod::mod == NULL
and mod::next == NULL, so the inner loop of static_call_del_module() will
neither find a module match nor a module chain. The next site in the walk
was either already converted, but can't match the module, or it will exit
the outer loop because it has a static_call_site pointer and not a
static_call_mod pointer.
static_call: Handle module init failure correctly in static_call_del_module()
Module insertion invokes static_call_add_module() to initialize the static
calls in a module. static_call_add_module() invokes __static_call_init(),
which allocates a struct static_call_mod to either encapsulate the built-in
static call sites of the associated key into it so further modules can be
added or to append the module to the module chain.
If that allocation fails the function returns with an error code and the
module core invokes static_call_del_module() to clean up eventually added
static_call_mod entries.
This works correctly, when all keys used by the module were converted over
to a module chain before the failure. If not then static_call_del_module()
causes a #GP as it blindly assumes that key::mods points to a valid struct
static_call_mod.
The problem is that key::mods is not a individual struct member of struct
static_call_key, it's part of a union to save space:
union {
/* bit 0: 0 = mods, 1 = sites */
unsigned long type;
struct static_call_mod *mods;
struct static_call_site *sites;
};
key::sites is a pointer to the list of built-in usage sites of the static
call. The type of the pointer is differentiated by bit 0. A mods pointer
has the bit clear, the sites pointer has the bit set.
As static_call_del_module() blidly assumes that the pointer is a valid
static_call_mod type, it fails to check for this failure case and
dereferences the pointer to the list of built-in call sites, which is
obviously bogus.
Cure it by checking whether the key has a sites or a mods pointer.
If it's a sites pointer then the key is not to be touched. As the sites are
walked in the same order as in __static_call_init() the site walk can be
terminated because all subsequent sites have not been touched by the init
code due to the error exit.
If it was converted before the allocation fail, then the inner loop which
searches for a module match will find nothing.
A fail in the second allocation in __static_call_init() is harmless and
does not require special treatment. The first allocation succeeded and
converted the key to a module chain. That first entry has mod::mod == NULL
and mod::next == NULL, so the inner loop of static_call_del_module() will
neither find a module match nor a module chain. The next site in the walk
was either already converted, but can't match the module, or it will exit
the outer loop because it has a static_call_site pointer and not a
static_call_mod pointer.
Affected Products
-
CVE record
-
NVD configurations
-
Red Hat packages
-
OpenCVE enrichment
No data
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||
| Linux | Linux | affected |
|
Configuration 1 [-]
|
| Package | CPE | Advisory | Released Date |
|---|---|---|---|
| Red Hat Enterprise Linux 9 | |||
| kernel-0:5.14.0-570.12.1.el9_6 | cpe:/a:redhat:enterprise_linux:9 | RHSA-2025:6966 | 2025-05-13T00:00:00Z |
| kernel-0:5.14.0-570.12.1.el9_6 | cpe:/o:redhat:enterprise_linux:9 | RHSA-2025:6966 | 2025-05-13T00:00:00Z |
No data available yet.
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 Debian DLA |
DLA-4008-1 | linux-6.1 security update |
 Ubuntu USN |
USN-7166-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7166-2 | Linux kernel (AWS) vulnerabilities |
| Ubuntu USN |
USN-7166-3 | Linux kernel (HWE) vulnerabilities |
| Ubuntu USN |
USN-7166-4 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
| Ubuntu USN |
USN-7186-1 | Linux kernel (Intel IoTG) vulnerabilities |
| Ubuntu USN |
USN-7186-2 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7194-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-7276-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7277-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7301-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7303-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7303-2 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7303-3 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7304-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7310-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7311-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7384-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-7384-2 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-7385-1 | Linux kernel (IBM) vulnerabilities |
| Ubuntu USN |
USN-7386-1 | Linux kernel (OEM) vulnerabilities |
| Ubuntu USN |
USN-7403-1 | Linux kernel (HWE) vulnerabilities |
| Ubuntu USN |
USN-7468-1 | Linux kernel (Azure, N-Series) vulnerabilities |
Metrics
No CVSS v4.0
Attack Vector Local
Attack Complexity Low
Privileges Required Low
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.238% probability within 30 days)
Exploitation none
Automatable no
Technical Impact partial
References
History
Nov 3, 2025 11:30 PM
Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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May 14, 2025 2:30 AM
First appearance in the feed. Affected versions updated. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
Oct 30, 2024 10:15 PM
First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-755 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
Oct 23, 2024 1:30 AM
Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Oct 22, 2024 2:15 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Oct 21, 2024 6:15 PM
Description updated. Title updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: static_call: Handle module init failure correctly in static_call_del_module() Module insertion invokes static_call_add_module() to initialize the static calls in a module. static_call_add_module() invokes __static_call_init(), which allocates a struct static_call_mod to either encapsulate the built-in static call sites of the associated key into it so further modules can be added or to append the module to the module chain. If that allocation fails the function returns with an error code and the module core invokes static_call_del_module() to clean up eventually added static_call_mod entries. This works correctly, when all keys used by the module were converted over to a module chain before the failure. If not then static_call_del_module() causes a #GP as it blindly assumes that key::mods points to a valid struct static_call_mod. The problem is that key::mods is not a individual struct member of struct static_call_key, it's part of a union to save space: union { /* bit 0: 0 = mods, 1 = sites */ unsigned long type; struct static_call_mod *mods; struct static_call_site *sites; }; key::sites is a pointer to the list of built-in usage sites of the static call. The type of the pointer is differentiated by bit 0. A mods pointer has the bit clear, the sites pointer has the bit set. As static_call_del_module() blidly assumes that the pointer is a valid static_call_mod type, it fails to check for this failure case and dereferences the pointer to the list of built-in call sites, which is obviously bogus. Cure it by checking whether the key has a sites or a mods pointer. If it's a sites pointer then the key is not to be touched. As the sites are walked in the same order as in __static_call_init() the site walk can be terminated because all subsequent sites have not been touched by the init code due to the error exit. If it was converted before the allocation fail, then the inner loop which searches for a module match will find nothing. A fail in the second allocation in __static_call_init() is harmless and does not require special treatment. The first allocation succeeded and converted the key to a module chain. That first entry has mod::mod == NULL and mod::next == NULL, so the inner loop of static_call_del_module() will neither find a module match nor a module chain. The next site in the walk was either already converted, but can't match the module, or it will exit the outer loop because it has a static_call_site pointer and not a static_call_mod pointer. | |
| Title | static_call: Handle module init failure correctly in static_call_del_module() | |
| References |
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Weaknesses
