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/trace/events/lock.h | 160 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 include/trace/events/lock.h (limited to 'include/trace/events/lock.h') diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h new file mode 100644 index 000000000..1ded869cd --- /dev/null +++ b/include/trace/events/lock.h @@ -0,0 +1,160 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM lock + +#if !defined(_TRACE_LOCK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_LOCK_H + +#include + +/* flags for lock:contention_begin */ +#define LCB_F_SPIN (1U << 0) +#define LCB_F_READ (1U << 1) +#define LCB_F_WRITE (1U << 2) +#define LCB_F_RT (1U << 3) +#define LCB_F_PERCPU (1U << 4) +#define LCB_F_MUTEX (1U << 5) + + +#ifdef CONFIG_LOCKDEP + +#include + +TRACE_EVENT(lock_acquire, + + TP_PROTO(struct lockdep_map *lock, unsigned int subclass, + int trylock, int read, int check, + struct lockdep_map *next_lock, unsigned long ip), + + TP_ARGS(lock, subclass, trylock, read, check, next_lock, ip), + + TP_STRUCT__entry( + __field(unsigned int, flags) + __string(name, lock->name) + __field(void *, lockdep_addr) + ), + + TP_fast_assign( + __entry->flags = (trylock ? 1 : 0) | (read ? 2 : 0); + __assign_str(name); + __entry->lockdep_addr = lock; + ), + + TP_printk("%p %s%s%s", __entry->lockdep_addr, + (__entry->flags & 1) ? "try " : "", + (__entry->flags & 2) ? "read " : "", + __get_str(name)) +); + +DECLARE_EVENT_CLASS(lock, + + TP_PROTO(struct lockdep_map *lock, unsigned long ip), + + TP_ARGS(lock, ip), + + TP_STRUCT__entry( + __string( name, lock->name ) + __field( void *, lockdep_addr ) + ), + + TP_fast_assign( + __assign_str(name); + __entry->lockdep_addr = lock; + ), + + TP_printk("%p %s", __entry->lockdep_addr, __get_str(name)) +); + +DEFINE_EVENT(lock, lock_release, + + TP_PROTO(struct lockdep_map *lock, unsigned long ip), + + TP_ARGS(lock, ip) +); + +#ifdef CONFIG_LOCK_STAT + +DEFINE_EVENT(lock, lock_contended, + + TP_PROTO(struct lockdep_map *lock, unsigned long ip), + + TP_ARGS(lock, ip) +); + +DEFINE_EVENT(lock, lock_acquired, + + TP_PROTO(struct lockdep_map *lock, unsigned long ip), + + TP_ARGS(lock, ip) +); + +#endif /* CONFIG_LOCK_STAT */ +#endif /* CONFIG_LOCKDEP */ + +TRACE_EVENT(contention_begin, + + TP_PROTO(void *lock, unsigned int flags), + + TP_ARGS(lock, flags), + + TP_STRUCT__entry( + __field(void *, lock_addr) + __field(unsigned int, flags) + ), + + TP_fast_assign( + __entry->lock_addr = lock; + __entry->flags = flags; + ), + + TP_printk("%p (flags=%s)", __entry->lock_addr, + __print_flags(__entry->flags, "|", + { LCB_F_SPIN, "SPIN" }, + { LCB_F_READ, "READ" }, + { LCB_F_WRITE, "WRITE" }, + { LCB_F_RT, "RT" }, + { LCB_F_PERCPU, "PERCPU" }, + { LCB_F_MUTEX, "MUTEX" } + )) +); + +TRACE_EVENT(contention_end, + + TP_PROTO(void *lock, int ret), + + TP_ARGS(lock, ret), + + TP_STRUCT__entry( + __field(void *, lock_addr) + __field(int, ret) + ), + + TP_fast_assign( + __entry->lock_addr = lock; + __entry->ret = ret; + ), + + TP_printk("%p (ret=%d)", __entry->lock_addr, __entry->ret) +); + +TRACE_EVENT(contended_release, + + TP_PROTO(void *lock), + + TP_ARGS(lock), + + TP_STRUCT__entry( + __field(void *, lock_addr) + ), + + TP_fast_assign( + __entry->lock_addr = lock; + ), + + TP_printk("%p", __entry->lock_addr) +); + +#endif /* _TRACE_LOCK_H */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1