Commit 49978aa8 authored by Cristian Marussi's avatar Cristian Marussi Committed by Catalin Marinas

kselftest: arm64: fake_sigreturn_bad_size

Add a simple fake_sigreturn testcase which builds a ucontext_t with a
badly sized header that causes a overrun in the __reserved area and
place it onto the stack. Expects a SIGSEGV on test PASS.
Reviewed-by: default avatarDave Martin <Dave.Martin@arm.com>
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 46185cd1
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 ARM Limited
*
* Place a fake sigframe on the stack including a bad record overflowing
* the __reserved space: on sigreturn Kernel must spot this attempt and
* the test case is expected to be terminated via SEGV.
*/
#include <signal.h>
#include <ucontext.h>
#include "test_signals_utils.h"
#include "testcases.h"
struct fake_sigframe sf;
#define MIN_SZ_ALIGN 16
static int fake_sigreturn_bad_size_run(struct tdescr *td,
siginfo_t *si, ucontext_t *uc)
{
size_t resv_sz, need_sz, offset;
struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
/* just to fill the ucontext_t with something real */
if (!get_current_context(td, &sf.uc))
return 1;
resv_sz = GET_SF_RESV_SIZE(sf);
/* at least HDR_SZ + bad sized esr_context needed */
need_sz = sizeof(struct esr_context) + HDR_SZ;
head = get_starting_head(shead, need_sz, resv_sz, &offset);
if (!head)
return 0;
/*
* Use an esr_context to build a fake header with a
* size greater then the free __reserved area minus HDR_SZ;
* using ESR_MAGIC here since it is not checked for size nor
* is limited to one instance.
*
* At first inject an additional normal esr_context
*/
head->magic = ESR_MAGIC;
head->size = sizeof(struct esr_context);
/* and terminate properly */
write_terminator_record(GET_RESV_NEXT_HEAD(head));
ASSERT_GOOD_CONTEXT(&sf.uc);
/*
* now mess with fake esr_context size: leaving less space than
* needed while keeping size value 16-aligned
*
* It must trigger a SEGV from Kernel on:
*
* resv_sz - offset < sizeof(*head)
*/
/* at first set the maximum good 16-aligned size */
head->size = (resv_sz - offset - need_sz + MIN_SZ_ALIGN) & ~0xfUL;
/* plus a bit more of 16-aligned sized stuff */
head->size += MIN_SZ_ALIGN;
/* and terminate properly */
write_terminator_record(GET_RESV_NEXT_HEAD(head));
ASSERT_BAD_CONTEXT(&sf.uc);
fake_sigreturn(&sf, sizeof(sf), 0);
return 1;
}
struct tdescr tde = {
.name = "FAKE_SIGRETURN_BAD_SIZE",
.descr = "Triggers a sigreturn with a overrun __reserved area",
.sig_ok = SIGSEGV,
.timeout = 3,
.run = fake_sigreturn_bad_size_run,
};
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment