ARM: missing ->mmap_sem around find_vma() in swp_emulate.c

[firefly-linux-kernel-4.4.55.git] / arch / arm / kernel / swp_emulate.c

diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index df745188f5de4abdf3bd04faaa5d31b653b0f210..ab1017bd1667d9772e01a903099aa665b3f86b7d 100644 (file)
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -109,10 +109,12 @@ static void set_segfault(struct pt_regs *regs, unsigned long addr)
 {
        siginfo_t info;
 
+       down_read(&current->mm->mmap_sem);
        if (find_vma(current->mm, addr) == NULL)
                info.si_code = SEGV_MAPERR;
        else
                info.si_code = SEGV_ACCERR;
+       up_read(&current->mm->mmap_sem);
 
        info.si_signo = SIGSEGV;
        info.si_errno = 0;