From be2d11b2a1e86586ace9f6839a159b170b00f2b3 Mon Sep 17 00:00:00 2001 From: Miroslav Benes Date: Wed, 27 Nov 2019 19:35:19 +0100 Subject: [PATCH] s390/unwind: add stack pointer alignment sanity checks ABI requires SP to be aligned 8 bytes, report unwinding error otherwise. Link: https://lkml.kernel.org/r/20191106095601.29986-5-mbenes@suse.cz Reviewed-by: Heiko Carstens Tested-by: Miroslav Benes Signed-off-by: Miroslav Benes Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dumpstack.c | 4 ++++ arch/s390/kernel/unwind_bc.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index d74e21a23703e..d306fe04489a4 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -94,6 +94,10 @@ int get_stack_info(unsigned long sp, struct task_struct *task, if (!sp) goto unknown; + /* Sanity check: ABI requires SP to be aligned 8 bytes. */ + if (sp & 0x7) + goto unknown; + /* Check per-task stack */ if (in_task_stack(sp, task, info)) goto recursion_check; diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c index ef42d5f77ce73..da2d4d4c5b0e0 100644 --- a/arch/s390/kernel/unwind_bc.c +++ b/arch/s390/kernel/unwind_bc.c @@ -92,6 +92,10 @@ bool unwind_next_frame(struct unwind_state *state) } } + /* Sanity check: ABI requires SP to be aligned 8 bytes. */ + if (sp & 0x7) + goto out_err; + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *) sp); /* Update unwind state */ -- 2.30.2