CVE-2024-39482

bcache: fix variable length array abuse in btree_iter

MEDIUM
5.5
CVSS Score
Published: July 5, 2024 at 06:55 AM UTC
Updated: October 15, 2026 at 01:18 AM UTC
7 products affected across 2 vendorsLinux KernelSIMATIC S7-1500 TM MFPRUGGEDCOM RST2428P Firmware

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: bcache: fix variable length array abuse in btree_iter btree_iter is used in two ways: either allocated on the stack with a fixed size MAX_BSETS, or from a mempool with a dynamic size based on the specific cache set. Previously, the struct had a fixed-length array of size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized iterators, which causes UBSAN to complain. This patch uses the same approach as in bcachefs's sort_iter and splits the iterator into a btree_iter with a flexible array member and a btree_iter_stack which embeds a btree_iter as well as a fixed-length data array.

Affected

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

All versions5.10 ≤ v < 5.10.2215.15 ≤ v < 5.15.1626.1 ≤ v < 6.1.946.6 ≤ v < 6.6.346.9 ≤ v < 6.9.53.10cafe563591446cf80bfbc2fe3bc72a2e36cf1060
Vendor states this is fixed in 0c31344e22dd8d6b1394c6e4c41d639015bdc671 (fixed)
Vendor states this is fixed in 2c3d7b03b658dc8bfa6112b194b67b92a87e081b (fixed)
Vendor states this is fixed in 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 (fixed)
Vendor states this is fixed in 5a1922adc5798b7ec894cd3f197afb6f9591b023 (fixed)
Vendor states this is fixed in 6479b9f41583b013041943c4602e1ad61cec8148 (fixed)
Vendor states this is fixed in 934e1e4331859183a861f396d7dfaf33cb5afb02 (fixed)
Vendor states this is fixed in 3.10 (unaffected)
Vendor states this is fixed in 5.10.221 (unaffected)
Vendor states this is fixed in 5.15.162 (unaffected)
Vendor states this is fixed in 6.1.94 (unaffected)
Vendor states this is fixed in 6.10 (unaffected)
Vendor states this is fixed in 6.6.34 (unaffected)
Vendor states this is fixed in 6.9.5 (unaffected)
v < V3.1
Affected range stops below V3.1, so it looks safe — our inference, not a vendor statement
v < V3.1
Affected range stops below V3.1, so it looks safe — our inference, not a vendor statement
v < V3.1
Affected range stops below V3.1, so it looks safe — our inference, not a vendor statement
v < V3.1
Affected range stops below V3.1, so it looks safe — our inference, not a vendor statement
v < V3.1
Affected range stops below V3.1, so it looks safe — our inference, not a vendor statement

References (9)

Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0c31344e22dd8d6b1394c6e4c41d639015bdc671
Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2c3d7b03b658dc8bfa6112b194b67b92a87e081b
Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31
Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5a1922adc5798b7ec894cd3f197afb6f9591b023
Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6479b9f41583b013041943c4602e1ad61cec8148
Mailing ListPatch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/934e1e4331859183a861f396d7dfaf33cb5afb02
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-265688.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-355557.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-770

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