CVE-2024-26665

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: túneles: corrige el acceso fuera de los límites al compilar el error IPv6 PMTU Si el error ICMPv6 se genera a partir de un skb no lineal, obtenemos el siguiente símbolo, ERROR: KASAN: slab-out- fuera de los límites en do_csum+0x220/0x240 Lectura de tamaño 4 en la dirección ffff88811d402c80 por tarea netperf/820 CPU: 0 PID: 820 Comm: netperf Not tainted 6.8.0-rc1+ #543 ... kasan_report+0xd8/0x110 do_csum+0x220 /0x240 csum_partial+0xc/0x20 skb_tunnel_check_pmtu+0xeb9/0x3280 vxlan_xmit_one+0x14c2/0x4080 vxlan_xmit+0xf61/0x5c00 dev_hard_start_xmit+0xfb/0x510 __dev_queue_xmit+0x7cd/0x32 a0 br_dev_queue_push_xmit+0x39d/0x6a0 Utilice skb_checksum en lugar de csum_partial, que no puede manejar SKB no lineales.

A flaw was found in the Linux kernel. This issue occurs due to the improper handling of non-linear skbs (socket buffers) when calculating checksums for ICMPv6 PMTU error messages. This vulnerability can lead to out-of-bounds access, potentially causing memory corruption or crashes.

In the Linux kernel, the following vulnerability has been resolved: tunnels: fix out of bounds access when building IPv6 PMTU error If the ICMPv6 error is built from a non-linear skb we get the following splat, BUG: KASAN: slab-out-of-bounds in do_csum+0x220/0x240 Read of size 4 at addr ffff88811d402c80 by task netperf/820 CPU: 0 PID: 820 Comm: netperf Not tainted 6.8.0-rc1+ #543 ... kasan_report+0xd8/0x110 do_csum+0x220/0x240 csum_partial+0xc/0x20 skb_tunnel_check_pmtu+0xeb9/0x3280 vxlan_xmit_one+0x14c2/0x4080 vxlan_xmit+0xf61/0x5c00 dev_hard_start_xmit+0xfb/0x510 __dev_queue_xmit+0x7cd/0x32a0 br_dev_queue_push_xmit+0x39d/0x6a0 Use skb_checksum instead of csum_partial who cannot deal with non-linear SKBs.

It was discovered that the Open vSwitch implementation in the Linux kernel could overflow its stack during recursive action operations under certain conditions. A local attacker could use this to cause a denial of service. Sander Wiebing, Alvise de Faveri Tron, Herbert Bos, and Cristiano Giuffrida discovered that the Linux kernel mitigations for the initial Branch History Injection vulnerability were insufficient for Intel processors. A local attacker could potentially use this to expose sensitive information.