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/task.h | 99 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 include/trace/events/task.h (limited to 'include/trace/events/task.h') diff --git a/include/trace/events/task.h b/include/trace/events/task.h new file mode 100644 index 000000000..b9a129eb5 --- /dev/null +++ b/include/trace/events/task.h @@ -0,0 +1,99 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM task + +#if !defined(_TRACE_TASK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_TASK_H +#include + +TRACE_EVENT(task_newtask, + + TP_PROTO(struct task_struct *task, u64 clone_flags), + + TP_ARGS(task, clone_flags), + + TP_STRUCT__entry( + __field( pid_t, pid) + __array( char, comm, TASK_COMM_LEN) + __field( u64, clone_flags) + __field( short, oom_score_adj) + ), + + TP_fast_assign( + __entry->pid = task->pid; + memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + __entry->clone_flags = clone_flags; + __entry->oom_score_adj = task->signal->oom_score_adj; + ), + + TP_printk("pid=%d comm=%s clone_flags=%llx oom_score_adj=%hd", + __entry->pid, __entry->comm, + __entry->clone_flags, __entry->oom_score_adj) +); + +TRACE_EVENT(task_rename, + + TP_PROTO(struct task_struct *task, const char *comm), + + TP_ARGS(task, comm), + + TP_STRUCT__entry( + __field( pid_t, pid) + __array( char, oldcomm, TASK_COMM_LEN) + __array( char, newcomm, TASK_COMM_LEN) + __field( short, oom_score_adj) + ), + + TP_fast_assign( + __entry->pid = task->pid; + memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN); + strscpy(entry->newcomm, comm, TASK_COMM_LEN); + __entry->oom_score_adj = task->signal->oom_score_adj; + ), + + TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%hd", + __entry->pid, __entry->oldcomm, + __entry->newcomm, __entry->oom_score_adj) +); + +/** + * task_prctl_unknown - called on unknown prctl() option + * @option: option passed + * @arg2: arg2 passed + * @arg3: arg3 passed + * @arg4: arg4 passed + * @arg5: arg5 passed + * + * Called on an unknown prctl() option. + */ +TRACE_EVENT(task_prctl_unknown, + + TP_PROTO(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5), + + TP_ARGS(option, arg2, arg3, arg4, arg5), + + TP_STRUCT__entry( + __field( int, option) + __field( unsigned long, arg2) + __field( unsigned long, arg3) + __field( unsigned long, arg4) + __field( unsigned long, arg5) + ), + + TP_fast_assign( + __entry->option = option; + __entry->arg2 = arg2; + __entry->arg3 = arg3; + __entry->arg4 = arg4; + __entry->arg5 = arg5; + ), + + TP_printk("option=%d arg2=%ld arg3=%ld arg4=%ld arg5=%ld", + __entry->option, __entry->arg2, __entry->arg3, __entry->arg4, __entry->arg5) +); + +#endif + +/* This part must be outside protection */ +#include -- cgit v1.3.1