CVE-2024-53142
initramfs: avoid filename buffer overrun
Published Dec 6, 2024
CVSS 3.1 · 7.8 High
EPSS < 1%
KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:
initramfs: avoid filename buffer overrun
The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:
37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
55 ============= ================== =========================
56 Field name Field size Meaning
57 ============= ================== =========================
...
70 c_namesize 8 bytes Length of filename, including final \0
When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().
If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.
Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
./reproducer.sh | gzip >> /myinitramfs
It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.
---- reproducer.sh ----
nilchar="A" # change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 )) # plus one to account for terminator
printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
$magic $ino $mode $uid $gid $nlink $mtime $filesize \
$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname
termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----
Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.
Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.
initramfs: avoid filename buffer overrun
The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:
37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
55 ============= ================== =========================
56 Field name Field size Meaning
57 ============= ================== =========================
...
70 c_namesize 8 bytes Length of filename, including final \0
When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().
If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.
Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
./reproducer.sh | gzip >> /myinitramfs
It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.
---- reproducer.sh ----
nilchar="A" # change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 )) # plus one to account for terminator
printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
$magic $ino $mode $uid $gid $nlink $mtime $filesize \
$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname
termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----
Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.
Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.
Analysis
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-4075-1 | linux security update |
| Debian DLA |
DLA-4076-1 | linux-6.1 security update |
 EUVD |
EUVD-2024-51814 | In the Linux kernel, the following vulnerability has been resolved: initramfs: avoid filename buffer overrun The initramfs filename field is defined in Documentation/driver-api/early-userspace/buffer-format.rst as: 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data ... 55 ============= ================== ========================= 56 Field name Field size Meaning 57 ============= ================== ========================= ... 70 c_namesize 8 bytes Length of filename, including final \0 When extracting an initramfs cpio archive, the kernel's do_name() path handler assumes a zero-terminated path at @collected, passing it directly to filp_open() / init_mkdir() / init_mknod(). If a specially crafted cpio entry carries a non-zero-terminated filename and is followed by uninitialized memory, then a file may be created with trailing characters that represent the uninitialized memory. The ability to create an initramfs entry would imply already having full control of the system, so the buffer overrun shouldn't be considered a security vulnerability. Append the output of the following bash script to an existing initramfs and observe any created /initramfs_test_fname_overrunAA* path. E.g. ./reproducer.sh | gzip >> /myinitramfs It's easiest to observe non-zero uninitialized memory when the output is gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(), rather than the initrd_start+initrd_size block. ---- reproducer.sh ---- nilchar="A" # change to "\0" to properly zero terminate / pad magic="070701" ino=1 mode=$(( 0100777 )) uid=0 gid=0 nlink=1 mtime=1 filesize=0 devmajor=0 devminor=1 rdevmajor=0 rdevminor=0 csum=0 fname="initramfs_test_fname_overrun" namelen=$(( ${#fname} + 1 )) # plus one to account for terminator printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \ $magic $ino $mode $uid $gid $nlink $mtime $filesize \ $devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) )) printf "%.s${nilchar}" $(seq 1 $termpadlen) ---- reproducer.sh ---- Symlink filename fields handled in do_symlink() won't overrun past the data segment, due to the explicit zero-termination of the symlink target. Fix filename buffer overrun by aborting the initramfs FSM if any cpio entry doesn't carry a zero-terminator at the expected (name_len - 1) offset. |
 Ubuntu USN |
USN-7276-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7277-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7310-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7387-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7387-2 | Linux kernel (FIPS) vulnerabilities |
| Ubuntu USN |
USN-7387-3 | Linux kernel (Real-time) vulnerabilities |
| Ubuntu USN |
USN-7388-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7389-1 | Linux kernel (NVIDIA Tegra) vulnerabilities |
| Ubuntu USN |
USN-7390-1 | Linux kernel (Xilinx ZynqMP) vulnerabilities |
| Ubuntu USN |
USN-7391-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7392-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7392-2 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7392-3 | Linux kernel (AWS) vulnerabilities |
| Ubuntu USN |
USN-7392-4 | Linux kernel (AWS FIPS) vulnerabilities |
| Ubuntu USN |
USN-7393-1 | Linux kernel (FIPS) vulnerabilities |
| Ubuntu USN |
USN-7401-1 | Linux kernel (AWS) vulnerabilities |
| Ubuntu USN |
USN-7407-1 | Linux kernel (HWE) vulnerabilities |
| Ubuntu USN |
USN-7413-1 | Linux kernel (IoT) vulnerabilities |
| Ubuntu USN |
USN-7421-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-7449-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7449-2 | Linux kernel (HWE) vulnerabilities |
| Ubuntu USN |
USN-7450-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7451-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7452-1 | Linux kernel vulnerabilities |
| Ubuntu USN |
USN-7453-1 | Linux kernel (Real-time) vulnerabilities |
| Ubuntu USN |
USN-7458-1 | Linux kernel (IBM) vulnerabilities |
| Ubuntu USN |
USN-7459-1 | Linux kernel (Intel IoTG) vulnerabilities |
| Ubuntu USN |
USN-7459-2 | Linux kernel (GCP) vulnerabilities |
| Ubuntu USN |
USN-7463-1 | Linux kernel (IBM) vulnerabilities |
| Ubuntu USN |
USN-7468-1 | Linux kernel (Azure, N-Series) vulnerabilities |
| Ubuntu USN |
USN-7523-1 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
| Ubuntu USN |
USN-7524-1 | Linux kernel (Raspberry Pi) vulnerabilities |
| Ubuntu USN |
USN-7539-1 | Linux kernel (Raspberry Pi) vulnerabilities |
| Ubuntu USN |
USN-7540-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Metrics
No CVSS v4.0
Attack Vector Local
Attack Complexity Low
Privileges Required Low
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
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% (0.248% probability within 30 days)
Key SSVC decision points have not yet been added.
References
History
Nov 3, 2025 9:30 PM
Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Jul 16, 2025 1:45 PM
Scoring metrics updated
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| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
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 |
Dec 17, 2024 2:00 AM
Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
Dec 14, 2024 9:00 PM
Added references
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| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Dec 10, 2024 7:45 PM
First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-787 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
Dec 9, 2024 11:00 AM
Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Dec 6, 2024 9:45 AM
Description updated. Title updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: initramfs: avoid filename buffer overrun The initramfs filename field is defined in Documentation/driver-api/early-userspace/buffer-format.rst as: 37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data ... 55 ============= ================== ========================= 56 Field name Field size Meaning 57 ============= ================== ========================= ... 70 c_namesize 8 bytes Length of filename, including final \0 When extracting an initramfs cpio archive, the kernel's do_name() path handler assumes a zero-terminated path at @collected, passing it directly to filp_open() / init_mkdir() / init_mknod(). If a specially crafted cpio entry carries a non-zero-terminated filename and is followed by uninitialized memory, then a file may be created with trailing characters that represent the uninitialized memory. The ability to create an initramfs entry would imply already having full control of the system, so the buffer overrun shouldn't be considered a security vulnerability. Append the output of the following bash script to an existing initramfs and observe any created /initramfs_test_fname_overrunAA* path. E.g. ./reproducer.sh | gzip >> /myinitramfs It's easiest to observe non-zero uninitialized memory when the output is gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(), rather than the initrd_start+initrd_size block. ---- reproducer.sh ---- nilchar="A" # change to "\0" to properly zero terminate / pad magic="070701" ino=1 mode=$(( 0100777 )) uid=0 gid=0 nlink=1 mtime=1 filesize=0 devmajor=0 devminor=1 rdevmajor=0 rdevminor=0 csum=0 fname="initramfs_test_fname_overrun" namelen=$(( ${#fname} + 1 )) # plus one to account for terminator printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \ $magic $ino $mode $uid $gid $nlink $mtime $filesize \ $devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) )) printf "%.s${nilchar}" $(seq 1 $termpadlen) ---- reproducer.sh ---- Symlink filename fields handled in do_symlink() won't overrun past the data segment, due to the explicit zero-termination of the symlink target. Fix filename buffer overrun by aborting the initramfs FSM if any cpio entry doesn't carry a zero-terminator at the expected (name_len - 1) offset. | |
| Title | initramfs: avoid filename buffer overrun | |
| References |
|
Subscriptions
Weaknesses
-
CWE-787
Out-of-bounds Write
