CVE-2026-43458
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
serial: caif: hold tty->link reference in ldisc_open and ser_release
A reproducer triggers a KASAN slab-use-after-free in pty_write_room()
when caif_serial's TX path calls tty_write_room(). The faulting access
is on tty->link->port.
Hold an extra kref on tty->link for the lifetime of the caif_serial line
discipline: get it in ldisc_open() and drop it in ser_release(), and
also drop it on the ldisc_open() error path.
With this change applied, the reproducer no longer triggers the UAF in
my testing.
https://git.kernel.org/stable/c/23a3ac2e2262a291498567418227b99e1f3606b1
https://git.kernel.org/stable/c/27e43356d0defb9fc7fa25265219a3ffeb7b3e98
https://git.kernel.org/stable/c/288598d80a068a0e9281de35bcb4ce495f189e2a
https://git.kernel.org/stable/c/35b58d3bc716ebb9ebd10fe1cac8c1177242511c
https://git.kernel.org/stable/c/52135420e9f75853ea0c6cea7b736e3e98495f7d
https://git.kernel.org/stable/c/8460187b4852fd00bd1c76394358053f3fa4d089
https://git.kernel.org/stable/c/97a0bb491cae39478c6225381f14e9ac67b7bba7
https://git.kernel.org/stable/c/ca2ceba983bb23ea0202c2882d963253416654a3