CVE-2026-43197

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 printksharedpbufs, 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)