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linux-user: check valid address in access_ok()

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Fix a crash with LTP testsuite and aarch64:

  tst_test.c:1015: INFO: Timeout per run is 0h 05m 00s
  qemu-aarch64: .../qemu/accel/tcg/translate-all.c:2522: page_check_range: Assertion `start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)' failed.
  qemu:handle_cpu_signal received signal outside vCPU context @ pc=0x60001554

page_check_range() should never be called with address outside the guest
address space. This patch adds a guest_addr_valid() check in access_ok()
to only call page_check_range() with a valid address.

Fixes: f6768aa1b4 ("target/arm: fix AArch64 virtual address space size")
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20190704084115.24713-1-lvivier@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Rémi Denis-Courmont 2019-07-04 10:41:15 +02:00 committed by Laurent Vivier
parent 4ced996ffe
commit 0acd4ab849
2 changed files with 7 additions and 1 deletions
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4
include/exec/cpu_ldst.h
View File

@ -62,7 +62,11 @@ typedef uint64_t abi_ptr;
/* All direct uses of g2h and h2g need to go away for usermode softmmu. */
#define g2h(x) ((void *)((unsigned long)(abi_ptr)(x) + guest_base))
#if HOST_LONG_BITS <= TARGET_VIRT_ADDR_SPACE_BITS
#define guest_addr_valid(x) (1)
#else
#define guest_addr_valid(x) ((x) <= GUEST_ADDR_MAX)
#endif
#define h2g_valid(x) guest_addr_valid((unsigned long)(x) - guest_base)
static inline int guest_range_valid(unsigned long start, unsigned long len)

4
linux-user/qemu.h
View File

@ -456,7 +456,9 @@ extern unsigned long guest_stack_size;
static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
{
return page_check_range((target_ulong)addr, size,
return guest_addr_valid(addr) &&
(size == 0 || guest_addr_valid(addr + size - 1)) &&
page_check_range((target_ulong)addr, size,
(type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | PAGE_WRITE)) == 0;
}