CVE-2026-43197

netconsole: avoid OOB reads, msg is not nul-terminated

State: Published
Severity: 9.1 Critical
Published: May 6, 2026
Updated: Oct 21, 2026
Reserved: May 1, 2026

Description

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

netconsole: avoid OOB reads, msg is not nul-terminated

msg passed to netconsole from the console subsystem is not guaranteed to be nul-terminated. Before recent commit 7eab73b18630 ("netconsole: convert to NBCON console infrastructure") the message would be placed in printk_shared_pbufs, a static global buffer, so KASAN had harder time catching OOB accesses. Now we see:

printk: console [netcon_ext0] enabled BUG: KASAN: slab-out-of-bounds in string+0x1f7/0x240 Read of size 1 at addr ffff88813b6d4c00 by task pr/netcon_ext0/594

CPU: 65 UID: 0 PID: 594 Comm: pr/netcon_ext0 Not tainted 6.19.0-11754-g4246fd6547c9 Call Trace: kasan_report+0xe4/0x120 string+0x1f7/0x240 vsnprintf+0x655/0xba0 scnprintf+0xba/0x120 netconsole_write+0x3fe/0xa10 nbcon_emit_next_record+0x46e/0x860 nbcon_kthread_func+0x623/0x750

Allocated by task 1: nbcon_alloc+0x1ea/0x450 register_console+0x26b/0xe10 init_netconsole+0xbb0/0xda0

The buggy address belongs to the object at ffff88813b6d4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes to the right of allocated 3072-byte region [ffff88813b6d4000, ffff88813b6d4c00)

Scores

CVSS	Score	Vector	Source
3.1	9.1 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H	Linux

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
LinuxLinux	c62c0a17f9b7398022f9eebe547878033264f81f to before 68fe91df6ea822dae772fceaad0686e4f5839aecAffected c62c0a17f9b7398022f9eebe547878033264f81f to before 8fe132c4873f9eb1b86ddbf31216e9d961a0b8b9Affected c62c0a17f9b7398022f9eebe547878033264f81f to before 3126a2f98beaec5a554a1fb31c46db1e8542665eAffected c62c0a17f9b7398022f9eebe547878033264f81f to before 74ab1456eaa3b2eb986138f9e1f4cb37e73b6f58Affected c62c0a17f9b7398022f9eebe547878033264f81f to before 82aec772fca2223bc5774bd9af486fd95766e578Affected
LinuxLinux	6.6Affected before 6.6Not affected 6.6.160 through 6.6.Not affected 6.12.103 through 6.12.Not affected 6.18.16 through 6.18.Not affected 6.19.6 through 6.19.Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

c62c0a17f9b7398022f9eebe547878033264f81f to before 68fe91df6ea822dae772fceaad0686e4f5839aecAffected
c62c0a17f9b7398022f9eebe547878033264f81f to before 8fe132c4873f9eb1b86ddbf31216e9d961a0b8b9Affected
c62c0a17f9b7398022f9eebe547878033264f81f to before 3126a2f98beaec5a554a1fb31c46db1e8542665eAffected
c62c0a17f9b7398022f9eebe547878033264f81f to before 74ab1456eaa3b2eb986138f9e1f4cb37e73b6f58Affected
c62c0a17f9b7398022f9eebe547878033264f81f to before 82aec772fca2223bc5774bd9af486fd95766e578Affected

LinuxLinux

6.6Affected
before 6.6Not affected
6.6.160 through 6.6.*Not affected
6.12.103 through 6.12.*Not affected
6.18.16 through 6.18.*Not affected
6.19.6 through 6.19.*Not affected
7.0 and laterNot affected

References

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