Description

In the Linux kernel, the following vulnerability has been resolved: ipvlan: Fix out-of-bound bugs caused by unset skb->mac_header If an AF_PACKET socket is used to send packets through ipvlan and the default xmit function of the AF_PACKET socket is changed from dev_queue_xmit() to packet_direct_xmit() via setsockopt() with the option name of PACKET_QDISC_BYPASS, the skb->mac_header may not be reset and remains as the initial value of 65535, this may trigger slab-out-of-bounds bugs as following: ================================================================= UG: KASAN: slab-out-of-bounds in ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan] PU: 2 PID: 1768 Comm: raw_send Kdump: loaded Not tainted 6.0.0-rc4+ #6 ardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 all Trace: print_address_description.constprop.0+0x1d/0x160 print_report.cold+0x4f/0x112 kasan_report+0xa3/0x130 ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan] ipvlan_start_xmit+0x29/0xa0 [ipvlan] __dev_direct_xmit+0x2e2/0x380 packet_direct_xmit+0x22/0x60 packet_snd+0x7c9/0xc40 sock_sendmsg+0x9a/0xa0 __sys_sendto+0x18a/0x230 __x64_sys_sendto+0x74/0x90 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is: 1. packet_snd() only reset skb->mac_header when sock->type is SOCK_RAW and skb->protocol is not specified as in packet_parse_headers() 2. packet_direct_xmit() doesn't reset skb->mac_header as dev_queue_xmit() In this case, skb->mac_header is 65535 when ipvlan_xmit_mode_l2() is called. So when ipvlan_xmit_mode_l2() gets mac header with eth_hdr() which use "skb->head + skb->mac_header", out-of-bound access occurs. This patch replaces eth_hdr() with skb_eth_hdr() in ipvlan_xmit_mode_l2() and reset mac header in multicast to solve this out-of-bound bug.

Severity

 

CVSS Version 3.x CVSS Version 2.0

CVSS 3.x Severity and Metrics:

NIST: NVD

Base Score:  N/A

NVD assessment not yet provided.

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

CVSS 2.0 Severity and Metrics:

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

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

ipvlan: Fix out-of-bound bugs caused by unset skb->mac_header

If an AF_PACKET socket is used to send packets through ipvlan and the
default xmit function of the AF_PACKET socket is changed from
dev_queue_xmit() to packet_direct_xmit() via setsockopt() with the option
name of PACKET_QDISC_BYPASS, the skb->mac_header may not be reset and
remains as the initial value of 65535, this may trigger slab-out-of-bounds
bugs as following

kernel.org https://git.kernel.org/stable/c/25efdbe5fe542c3063d1948cc4e98abcb57621ca [No types assigned]

kernel.org https://git.kernel.org/stable/c/346e94aa4a99378592c46d6a34c72703a32bd5be [No types assigned]

kernel.org https://git.kernel.org/stable/c/81225b2ea161af48e093f58e8dfee6d705b16af4 [No types assigned]

kernel.org https://git.kernel.org/stable/c/8d06006c7eb75587d986da46c48ba9274f94e8e7 [No types assigned]

kernel.org https://git.kernel.org/stable/c/ab4a733874ead120691e8038272d22f8444d3638 [No types assigned]

kernel.org https://git.kernel.org/stable/c/b583e6b25bf9321c91154f6c78d2173ef12c4241 [No types assigned]

kernel.org https://git.kernel.org/stable/c/bffcdade259c05ab3436b5fab711612093c275ef [No types assigned]

kernel.org https://git.kernel.org/stable/c/e2b46cd5796f083e452fbc624f65b80328b0c1a4 [No types assigned]