From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- include/net/ip6_checksum.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 include/net/ip6_checksum.h (limited to 'include/net/ip6_checksum.h') diff --git a/include/net/ip6_checksum.h b/include/net/ip6_checksum.h new file mode 100644 index 000000000..6677b3cc3 --- /dev/null +++ b/include/net/ip6_checksum.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Checksumming functions for IPv6 + * + * Authors: Jorge Cwik, + * Arnt Gulbrandsen, + * Borrows very liberally from tcp.c and ip.c, see those + * files for more names. + */ + +/* + * Fixes: + * + * Ralf Baechle : generic ipv6 checksum + * + */ + +#ifndef _CHECKSUM_IPV6_H +#define _CHECKSUM_IPV6_H + +#include +#include +#include +#include +#include +#include +#include + +#ifndef _HAVE_ARCH_IPV6_CSUM +__sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, __wsum csum); +#endif + +static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto) +{ + return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, + &ipv6_hdr(skb)->daddr, + skb->len, proto, 0)); +} + +static __inline__ __sum16 tcp_v6_check(int len, + const struct in6_addr *saddr, + const struct in6_addr *daddr, + __wsum base) +{ + return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base); +} + +static inline void __tcp_v6_send_check(struct sk_buff *skb, + const struct in6_addr *saddr, + const struct in6_addr *daddr) +{ + struct tcphdr *th = tcp_hdr(skb); + + th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct tcphdr, check); +} + +static inline void tcp_v6_gso_csum_prep(struct sk_buff *skb) +{ + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct tcphdr *th = tcp_hdr(skb); + + ipv6h->payload_len = 0; + th->check = ~tcp_v6_check(0, &ipv6h->saddr, &ipv6h->daddr, 0); +} + +static inline __sum16 udp_v6_check(int len, + const struct in6_addr *saddr, + const struct in6_addr *daddr, + __wsum base) +{ + return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base); +} + +void udp6_set_csum(bool nocheck, struct sk_buff *skb, + const struct in6_addr *saddr, + const struct in6_addr *daddr, int len); +#endif -- cgit v1.3.1