diff options
Diffstat (limited to 'arch/x86/kernel/unwind_frame.c')
| -rw-r--r-- | arch/x86/kernel/unwind_frame.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index a2456d4d286a..9b8b3cb2e934 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -6,6 +6,21 @@ #define FRAME_HEADER_SIZE (sizeof(long) * 2) +/* + * This disables KASAN checking when reading a value from another task's stack, + * since the other task could be running on another CPU and could have poisoned + * the stack in the meantime. + */ +#define READ_ONCE_TASK_STACK(task, x) \ +({ \ + unsigned long val; \ + if (task == current) \ + val = READ_ONCE(x); \ + else \ + val = READ_ONCE_NOCHECK(x); \ + val; \ +}) + unsigned long unwind_get_return_address(struct unwind_state *state) { unsigned long addr; @@ -14,7 +29,8 @@ unsigned long unwind_get_return_address(struct unwind_state *state) if (unwind_done(state)) return 0; - addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p, + addr = READ_ONCE_TASK_STACK(state->task, *addr_p); + addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, addr, addr_p); return __kernel_text_address(addr) ? addr : 0; @@ -48,7 +64,7 @@ bool unwind_next_frame(struct unwind_state *state) if (unwind_done(state)) return false; - next_bp = (unsigned long *)*state->bp; + next_bp = (unsigned long *)READ_ONCE_TASK_STACK(state->task,*state->bp); /* make sure the next frame's data is accessible */ if (!update_stack_state(state, next_bp, FRAME_HEADER_SIZE)) |