Vigil@nce - Linux kernel: NULL pointer dereference via slhc_init
October 2015 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
A local attacker can force a NULL pointer to be dereferenced in
the slhc_init() function of the Linux kernel, in order to trigger
a denial of service.
– Impacted products: Linux.
– Severity: 1/4.
– Creation date: 12/10/2015.
DESCRIPTION OF THE VULNERABILITY
The Linux kernel implements the PPPIOCSMAXCID ioctl, which defines
the maximal size of entries for PPP compression.
This ioctl calls the slhc_init() function of the
drivers/net/slip/slhc.c file. However, if the size is too large,
the comp->tstate pointer becomes NULL, and this function does not
check if this pointer is NULL, before using it.
A local attacker can therefore force a NULL pointer to be
dereferenced in the slhc_init() function of the Linux kernel, in
order to trigger a denial of service.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/Linux-kernel-NULL-pointer-dereference-via-slhc-init-18071