CVE-2024-49958

ocfs2: reserve space for inline xattr before attaching reflink tree

MEDIUM

5.5

CVSS Score

Published: October 21, 2024 at 06:02 PM UTC

Updated: August 5, 2026 at 12:05 PM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM5.5

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

v ≥ 3.0.87v ≥ 3.10.2v ≥ 3.2.49v ≥ 3.4.54v ≥ 3.9.113.0.87 ≤ v < 3.13.0.87 ≤ v < 3.23.10.2 ≤ v < 3.113.11 ≤ v < 4.19.3233.11 ≤ v < 5.10.2273.11 ≤ v < 5.15.1683.11 ≤ v < 5.4.2853.11 ≤ v < 6.1.1133.11 ≤ v < 6.10.143.11 ≤ v < 6.11.33.11 ≤ v < 6.123.11 ≤ v < 6.6.553.2.49 ≤ v < 3.33.2.49 ≤ v < 3.43.4.54 ≤ v < 3.53.4.54 ≤ v < 3.93.9.11 ≤ v < 3.105.11 ≤ v < 5.15.1685.16 ≤ v < 6.1.1136.11 ≤ v < 6.11.36.2 ≤ v < 6.6.556.7 ≤ v < 6.10.141926bf8ae44d80c9f50103f11fc4f17e2e2bf6841e7e4c9ae2a78a6791a2ca91a6a400f94855f01e26a849f49fb3347d126a0ed6611173f903374ef43.0.87 3.10.2 3.11 3.2.49 3.4.54 3.9.113a32958d2ac96070c53d04bd8e013c97b260b5e693f26306db89c9dc37885b76a1082e6d54d23b16ef962df057aaafd714f5c22ba3de1be459571fdf

Vendor states this is fixed in 020f5c53c17f66c0a8f2d37dad27ace301b8d8a1 (fixed)

Vendor states this is fixed in 5c2072f02c0d75802ec28ec703b7d43a0dd008b5 (fixed)

Vendor states this is fixed in 5c9807c523b4fca81d3e8e864dabc8c806402121 (fixed)

Vendor states this is fixed in 5ca60b86f57a4d9648f68418a725b3a7de2816b0 (fixed)

Vendor states this is fixed in 637c00e06564a945e9d0edb3d78d362d64935f9f (fixed)

Vendor states this is fixed in 74364cb578dcc0b6c9109519d19cbe5a56afac9a (fixed)

Vendor states this is fixed in 96ce4c3537114d1698be635f5e36c62dc49df7a4 (fixed)

Vendor states this is fixed in 9f9a8f3ac65b4147f1a7b6c05fad5192c0e3c3d9 (fixed)

Vendor states this is fixed in aac31d654a0a31cb0d2fa36ae694f4e164a52707 (fixed)

Affected range stops below 3.1, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.10, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 3.11 (unaffected)

Affected range stops below 3.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.4, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.5, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.9, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 4.19.323 (unaffected)

Vendor states this is fixed in 5.10.227 (unaffected)

Vendor states this is fixed in 5.15.168 (unaffected)

Vendor states this is fixed in 5.4.285 (unaffected)

Vendor states this is fixed in 6.1.113 (unaffected)

Vendor states this is fixed in 6.10.14 (unaffected)

Vendor states this is fixed in 6.11.3 (unaffected)

Vendor states this is fixed in 6.12 (unaffected)

Vendor states this is fixed in 6.6.55 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references