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/siox.h | 66 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 include/trace/events/siox.h (limited to 'include/trace/events/siox.h') diff --git a/include/trace/events/siox.h b/include/trace/events/siox.h new file mode 100644 index 000000000..68a43fc2c --- /dev/null +++ b/include/trace/events/siox.h @@ -0,0 +1,66 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM siox + +#if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_SIOX_H + +#include + +TRACE_EVENT(siox_set_data, + TP_PROTO(const struct siox_master *smaster, + const struct siox_device *sdevice, + unsigned int devno, size_t bufoffset), + TP_ARGS(smaster, sdevice, devno, bufoffset), + TP_STRUCT__entry( + __field(int, busno) + __field(unsigned int, devno) + __field(size_t, inbytes) + __dynamic_array(u8, buf, sdevice->inbytes) + ), + TP_fast_assign( + __entry->busno = smaster->busno; + __entry->devno = devno; + __entry->inbytes = sdevice->inbytes; + memcpy(__get_dynamic_array(buf), + smaster->buf + bufoffset, sdevice->inbytes); + ), + TP_printk("siox-%d-%u [%*phD]", + __entry->busno, + __entry->devno, + (int)__entry->inbytes, __get_dynamic_array(buf) + ) +); + +TRACE_EVENT(siox_get_data, + TP_PROTO(const struct siox_master *smaster, + const struct siox_device *sdevice, + unsigned int devno, u8 status_clean, + size_t bufoffset), + TP_ARGS(smaster, sdevice, devno, status_clean, bufoffset), + TP_STRUCT__entry( + __field(int, busno) + __field(unsigned int, devno) + __field(u8, status_clean) + __field(size_t, outbytes) + __dynamic_array(u8, buf, sdevice->outbytes) + ), + TP_fast_assign( + __entry->busno = smaster->busno; + __entry->devno = devno; + __entry->status_clean = status_clean; + __entry->outbytes = sdevice->outbytes; + memcpy(__get_dynamic_array(buf), + smaster->buf + bufoffset, sdevice->outbytes); + ), + TP_printk("siox-%d-%u (%02hhx) [%*phD]", + __entry->busno, + __entry->devno, + __entry->status_clean, + (int)__entry->outbytes, __get_dynamic_array(buf) + ) +); + +#endif /* if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ) */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1