CVE-2024-40966

2024-07-1213:15:18

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux

kernel

tty

vulnerability

fix

virtual terminals

n_tty

con_write

n_gsm

gsmld_write

EPSS

Percentile

15.9%

JSON

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

tty: add the option to have a tty reject a new ldisc

… and use it to limit the virtual terminals to just N_TTY. They are
kind of special, and in particular, the “con_write()” routine violates
the “writes cannot sleep” rule that some ldiscs rely on.

This avoids the

BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659

when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock.