// For flags

CVE-2024-49958

ocfs2: reserve space for inline xattr before attaching reflink tree

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: ocfs2: reserve space for inline xattr before attaching reflink tree One of our customers reported a crash and a corrupted ocfs2 filesystem. The crash was due to the detection of corruption. Upon troubleshooting,
the fsck -fn output showed the below corruption [EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record,
but fsck believes the largest valid value is 227. Clamp the next record value? n The stat output from the debugfs.ocfs2 showed the following corruption
where the "Next Free Rec:" had overshot the "Count:" in the root metadata
block. Inode: 33080590 Mode: 0640 Generation: 2619713622 (0x9c25a856) FS Generation: 904309833 (0x35e6ac49) CRC32: 00000000 ECC: 0000 Type: Regular Attr: 0x0 Flags: Valid Dynamic Features: (0x16) HasXattr InlineXattr Refcounted Extended Attributes Block: 0 Extended Attributes Inline Size: 256 User: 0 (root) Group: 0 (root) Size: 281320357888 Links: 1 Clusters: 141738 ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024 atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024 mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024 dtime: 0x0 -- Wed Dec 31 17:00:00 1969 Refcount Block: 2777346 Last Extblk: 2886943 Orphan Slot: 0 Sub Alloc Slot: 0 Sub Alloc Bit: 14 Tree Depth: 1 Count: 227 Next Free Rec: 230 ## Offset Clusters Block# 0 0 2310 2776351 1 2310 2139 2777375 2 4449 1221 2778399 3 5670 731 2779423 4 6401 566 2780447 ....... .... ....... ....... .... ....... The issue was in the reflink workfow while reserving space for inline
xattr. The problematic function is ocfs2_reflink_xattr_inline(). By the
time this function is called the reflink tree is already recreated at the
destination inode from the source inode. At this point, this function
reserves space for inline xattrs at the destination inode without even
checking if there is space at the root metadata block. It simply reduces
the l_count from 243 to 227 thereby making space of 256 bytes for inline
xattr whereas the inode already has extents beyond this index (in this
case up to 230), thereby causing corruption. The fix for this is to reserve space for inline metadata at the destination
inode before the reflink tree gets recreated. The customer has verified the
fix.

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reserve space for inline xattr before attaching reflink tree One of our customers reported a crash and a corrupted ocfs2 filesystem. The crash was due to the detection of corruption. Upon troubleshooting, the fsck -fn output showed the below corruption [EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record, but fsck believes the largest valid value is 227. Clamp the next record value? n The stat output from the debugfs.ocfs2 showed the following corruption where the "Next Free Rec:" had overshot the "Count:" in the root metadata block. Inode: 33080590 Mode: 0640 Generation: 2619713622 (0x9c25a856) FS Generation: 904309833 (0x35e6ac49) CRC32: 00000000 ECC: 0000 Type: Regular Attr: 0x0 Flags: Valid Dynamic Features: (0x16) HasXattr InlineXattr Refcounted Extended Attributes Block: 0 Extended Attributes Inline Size: 256 User: 0 (root) Group: 0 (root) Size: 281320357888 Links: 1 Clusters: 141738 ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024 atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024 mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024 dtime: 0x0 -- Wed Dec 31 17:00:00 1969 Refcount Block: 2777346 Last Extblk: 2886943 Orphan Slot: 0 Sub Alloc Slot: 0 Sub Alloc Bit: 14 Tree Depth: 1 Count: 227 Next Free Rec: 230 ## Offset Clusters Block# 0 0 2310 2776351 1 2310 2139 2777375 2 4449 1221 2778399 3 5670 731 2779423 4 6401 566 2780447 ....... .... ....... ....... .... ....... The issue was in the reflink workfow while reserving space for inline xattr. The problematic function is ocfs2_reflink_xattr_inline(). By the time this function is called the reflink tree is already recreated at the destination inode from the source inode. At this point, this function reserves space for inline xattrs at the destination inode without even checking if there is space at the root metadata block. It simply reduces the l_count from 243 to 227 thereby making space of 256 bytes for inline xattr whereas the inode already has extents beyond this index (in this case up to 230), thereby causing corruption. The fix for this is to reserve space for inline metadata at the destination inode before the reflink tree gets recreated. The customer has verified the fix.

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"
>= 3.11 < 4.19.323
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 4.19.323"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 5.4.285
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 5.4.285"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 5.10.227
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 5.10.227"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 5.15.168
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 5.15.168"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 6.1.113
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 6.1.113"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 6.6.55
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 6.6.55"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 6.10.14
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 6.10.14"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 6.11.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 6.11.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 3.11 < 6.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 3.11 < 6.12"
en
Affected
Linux
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Linux Kernel
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3.0.87
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en
Affected
Linux
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Linux Kernel
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3.2.49
Search vendor "Linux" for product "Linux Kernel" and version "3.2.49"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
3.4.54
Search vendor "Linux" for product "Linux Kernel" and version "3.4.54"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
3.9.11
Search vendor "Linux" for product "Linux Kernel" and version "3.9.11"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
3.10.2
Search vendor "Linux" for product "Linux Kernel" and version "3.10.2"
en
Affected