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/ife.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 include/net/ife.h (limited to 'include/net/ife.h') diff --git a/include/net/ife.h b/include/net/ife.h new file mode 100644 index 000000000..7e2538d85 --- /dev/null +++ b/include/net/ife.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_IFE_H +#define __NET_IFE_H + +#include +#include +#include + +#if IS_ENABLED(CONFIG_NET_IFE) + +void *ife_encode(struct sk_buff *skb, u16 metalen); +void *ife_decode(struct sk_buff *skb, u16 *metalen); + +void *ife_tlv_meta_decode(void *skbdata, const void *ifehdr_end, u16 *attrtype, + u16 *dlen, u16 *totlen); +int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, + const void *dval); + +void *ife_tlv_meta_next(void *skbdata); + +#else + +static inline void *ife_encode(struct sk_buff *skb, u16 metalen) +{ + return NULL; +} + +static inline void *ife_decode(struct sk_buff *skb, u16 *metalen) +{ + return NULL; +} + +static inline void *ife_tlv_meta_decode(void *skbdata, u16 *attrtype, u16 *dlen, + u16 *totlen) +{ + return NULL; +} + +static inline int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, + const void *dval) +{ + return 0; +} + +static inline void *ife_tlv_meta_next(void *skbdata) +{ + return NULL; +} + +#endif + +#endif /* __NET_IFE_H */ -- cgit v1.3.1