// For flags

CVE-2024-50015

ext4: dax: fix overflowing extents beyond inode size when partially writing

Severity Score

5.5
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved: ext4: dax: fix overflowing extents beyond inode size when partially writing The dax_iomap_rw() does two things in each iteration: map written blocks
and copy user data to blocks. If the process is killed by user(See signal
handling in dax_iomap_iter()), the copied data will be returned and added
on inode size, which means that the length of written extents may exceed
the inode size, then fsck will fail. An example is given as: dd if=/dev/urandom of=file bs=4M count=1 dax_iomap_rw iomap_iter // round 1 ext4_iomap_begin ext4_iomap_alloc // allocate 0~2M extents(written flag) dax_iomap_iter // copy 2M data iomap_iter // round 2 iomap_iter_advance iter->pos += iter->processed // iter->pos = 2M ext4_iomap_begin ext4_iomap_alloc // allocate 2~4M extents(written flag) dax_iomap_iter fatal_signal_pending done = iter->pos - iocb->ki_pos // done = 2M ext4_handle_inode_extension ext4_update_inode_size // inode size = 2M fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix? Fix the problem by truncating extents if the written length is smaller
than expected.

In the Linux kernel, the following vulnerability has been resolved: ext4: dax: fix overflowing extents beyond inode size when partially writing The dax_iomap_rw() does two things in each iteration: map written blocks and copy user data to blocks. If the process is killed by user(See signal handling in dax_iomap_iter()), the copied data will be returned and added on inode size, which means that the length of written extents may exceed the inode size, then fsck will fail. An example is given as: dd if=/dev/urandom of=file bs=4M count=1 dax_iomap_rw iomap_iter // round 1 ext4_iomap_begin ext4_iomap_alloc // allocate 0~2M extents(written flag) dax_iomap_iter // copy 2M data iomap_iter // round 2 iomap_iter_advance iter->pos += iter->processed // iter->pos = 2M ext4_iomap_begin ext4_iomap_alloc // allocate 2~4M extents(written flag) dax_iomap_iter fatal_signal_pending done = iter->pos - iocb->ki_pos // done = 2M ext4_handle_inode_extension ext4_update_inode_size // inode size = 2M fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix? Fix the problem by truncating extents if the written length is smaller than expected.

Michael Randrianantenaina discovered that the Bluetooth driver in the Linux Kernel contained an improper access control vulnerability. A nearby attacker could use this to connect a rougue device and possibly execute arbitrary code. Attila Szász discovered that the HFS+ file system implementation in the Linux Kernel contained a heap overflow vulnerability. An attacker could use a specially crafted file system image that, when mounted, could cause a denial of service or possibly execute arbitrary code.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-10-21 CVE Reserved
  • 2024-10-21 CVE Published
  • 2024-12-19 CVE Updated
  • 2025-03-31 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 5.10.227
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 5.10.227"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 5.15.168
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 5.15.168"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 6.1.113
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 6.1.113"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 6.6.55
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 6.6.55"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 6.10.14
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 6.10.14"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 6.11.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 6.11.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.10 < 6.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.10 < 6.12"
en
Affected