CVE-2023-53752 - Vulnerability Details

- net: deal with integer overflows in kmalloc_reserve()

Description

In the Linux kernel, the following vulnerability has been resolved:

net: deal with integer overflows in kmalloc_reserve()

Blamed commit changed:
ptr = kmalloc(size);
if (ptr)
size = ksize(ptr);

size = kmalloc_size_roundup(size);
ptr = kmalloc(size);

This allowed various crash as reported by syzbot [1]
and Kyle Zeng.

Problem is that if @size is bigger than 0x80000001,
kmalloc_size_roundup(size) returns 2^32.

kmalloc_reserve() uses a 32bit variable (obj_size),
so 2^32 is truncated to 0.

kmalloc(0) returns ZERO_SIZE_PTR which is not handled by
skb allocations.

Following trace can be triggered if a netdev->mtu is set
close to 0x7fffffff

We might in the future limit netdev->mtu to more sensible
limit (like KMALLOC_MAX_SIZE).

This patch is based on a syzbot report, and also a report
and tentative fix from Kyle Zeng.

[1]
BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline]
BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527
Write of size 32 at addr 00000000fffffd10 by task syz-executor.4/22554

CPU: 1 PID: 22554 Comm: syz-executor.4 Not tainted 6.1.39-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:279
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:286
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x120/0x1a0 lib/dump_stack.c:106
print_report+0xe4/0x4b4 mm/kasan/report.c:398
kasan_report+0x150/0x1ac mm/kasan/report.c:495
kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189
memset+0x40/0x70 mm/kasan/shadow.c:44
__build_skb_around net/core/skbuff.c:294 [inline]
__alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527
alloc_skb include/linux/skbuff.h:1316 [inline]
igmpv3_newpack+0x104/0x1088 net/ipv4/igmp.c:359
add_grec+0x81c/0x1124 net/ipv4/igmp.c:534
igmpv3_send_cr net/ipv4/igmp.c:667 [inline]
igmp_ifc_timer_expire+0x1b0/0x1008 net/ipv4/igmp.c:810
call_timer_fn+0x1c0/0x9f0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x54c/0x710 kernel/time/timer.c:1790
run_timer_softirq+0x28/0x4c kernel/time/timer.c:1803
_stext+0x380/0xfbc
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:891
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84
invoke_softirq kernel/softirq.c:437 [inline]
__irq_exit_rcu+0x1c0/0x4cc kernel/softirq.c:683
irq_exit_rcu+0x14/0x78 kernel/softirq.c:695
el0_interrupt+0x7c/0x2e0 arch/arm64/kernel/entry-common.c:717
__el0_irq_handler_common+0x18/0x24 arch/arm64/kernel/entry-common.c:724
el0t_64_irq_handler+0x10/0x1c arch/arm64/kernel/entry-common.c:729
el0t_64_irq+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Published: 2025-12-08

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

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

unaffected

Version	Status	Constraints
`0dbc898f5917c5a3bec6be19d9f5469cbc351a7d`	affected	< 31cf7853a940181593e4472fc56f46574123f9f6
`12d6c1d3a2ad0c199ec57c201cdc71e8e157a232`	affected	< e4ffc47a1c3e5d11a853aa178c9a5136e79412e9
`12d6c1d3a2ad0c199ec57c201cdc71e8e157a232`	affected	< bf7da02d2b8faf324206e1cbe64a4813ff903cc1
`12d6c1d3a2ad0c199ec57c201cdc71e8e157a232`	affected	< 915d975b2ffa58a14bfcf16fafe00c41315949ff
`6.1.31`	affected	< 6.1.54

Linux

affected

Version	Status	Constraints
`6.2`	affected	—
`0`	unaffected	< 6.2
`6.1.54`	unaffected	≤ 6.1.*
`6.4.16`	unaffected	≤ 6.4.*
`6.5.3`	unaffected	≤ 6.5.*
`6.6`	unaffected	≤ *

No data.

No data available yet.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00021.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/31cf7853a940181593e4472fc56f46574123f9f6
https://git.kernel.org/stable/c/915d975b2ffa58a14bfcf16fafe00c41315949ff
https://git.kernel.org/stable/c/bf7da02d2b8faf324206e1cbe64a4813ff903cc1
https://git.kernel.org/stable/c/e4ffc47a1c3e5d11a853aa178c9a5136e79412e9
https://lore.kernel.org/linux-cve-announce/2025120843-CVE-2023-53752-339f@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2023-53752
https://www.cve.org/CVERecord?id=CVE-2023-53752

History

Tue, 09 Dec 2025 00:15:00 +0000

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2025120843-CVE-2023-53752-339f@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2023-53752 https://www.cve.org/CVERecord?id=CVE-2023-53752
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Low`

Mon, 08 Dec 2025 02:00:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: net: deal with integer overflows in kmalloc_reserve() Blamed commit changed: ptr = kmalloc(size); if (ptr) size = ksize(ptr); size = kmalloc_size_roundup(size); ptr = kmalloc(size); This allowed various crash as reported by syzbot [1] and Kyle Zeng. Problem is that if @size is bigger than 0x80000001, kmalloc_size_roundup(size) returns 2^32. kmalloc_reserve() uses a 32bit variable (obj_size), so 2^32 is truncated to 0. kmalloc(0) returns ZERO_SIZE_PTR which is not handled by skb allocations. Following trace can be triggered if a netdev->mtu is set close to 0x7fffffff We might in the future limit netdev->mtu to more sensible limit (like KMALLOC_MAX_SIZE). This patch is based on a syzbot report, and also a report and tentative fix from Kyle Zeng. [1] BUG: KASAN: user-memory-access in __build_skb_around net/core/skbuff.c:294 [inline] BUG: KASAN: user-memory-access in __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527 Write of size 32 at addr 00000000fffffd10 by task syz-executor.4/22554 CPU: 1 PID: 22554 Comm: syz-executor.4 Not tainted 6.1.39-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:279 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:286 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x120/0x1a0 lib/dump_stack.c:106 print_report+0xe4/0x4b4 mm/kasan/report.c:398 kasan_report+0x150/0x1ac mm/kasan/report.c:495 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189 memset+0x40/0x70 mm/kasan/shadow.c:44 __build_skb_around net/core/skbuff.c:294 [inline] __alloc_skb+0x3c4/0x6e8 net/core/skbuff.c:527 alloc_skb include/linux/skbuff.h:1316 [inline] igmpv3_newpack+0x104/0x1088 net/ipv4/igmp.c:359 add_grec+0x81c/0x1124 net/ipv4/igmp.c:534 igmpv3_send_cr net/ipv4/igmp.c:667 [inline] igmp_ifc_timer_expire+0x1b0/0x1008 net/ipv4/igmp.c:810 call_timer_fn+0x1c0/0x9f0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers+0x54c/0x710 kernel/time/timer.c:1790 run_timer_softirq+0x28/0x4c kernel/time/timer.c:1803 _stext+0x380/0xfbc ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:79 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:84 invoke_softirq kernel/softirq.c:437 [inline] __irq_exit_rcu+0x1c0/0x4cc kernel/softirq.c:683 irq_exit_rcu+0x14/0x78 kernel/softirq.c:695 el0_interrupt+0x7c/0x2e0 arch/arm64/kernel/entry-common.c:717 __el0_irq_handler_common+0x18/0x24 arch/arm64/kernel/entry-common.c:724 el0t_64_irq_handler+0x10/0x1c arch/arm64/kernel/entry-common.c:729 el0t_64_irq+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Title		net: deal with integer overflows in kmalloc_reserve()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/31cf7853a940181593e4472fc56f46574123f9f6 https://git.kernel.org/stable/c/915d975b2ffa58a14bfcf16fafe00c41315949ff https://git.kernel.org/stable/c/bf7da02d2b8faf324206e1cbe64a4813ff903cc1 https://git.kernel.org/stable/c/e4ffc47a1c3e5d11a853aa178c9a5136e79412e9

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-12-08T01:19:12.407Z

Updated: 2026-05-23T15:30:46.353Z

Reserved: 2025-12-08T01:18:04.279Z

Link: CVE-2023-53752

Vulnrichment

No data.

NVD

Status : Deferred

Published: 2025-12-08T02:15:50.713

Modified: 2026-04-15T00:35:42.020

Link: CVE-2023-53752

Redhat

Severity : Low

Publid Date: 2025-12-08T00:00:00Z

Links: CVE-2023-53752 - Bugzilla

OpenCVE Enrichment

No data.

Weaknesses

No weakness.

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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