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// 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, sizeof(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,
};
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