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-rw-r--r--arch/x86/entry/vsyscall/vsyscall_64.c28
1 files changed, 2 insertions, 26 deletions
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index e0ca8120ae..1245000a87 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -98,11 +98,6 @@ static int addr_to_vsyscall_nr(unsigned long addr)
static bool write_ok_or_segv(unsigned long ptr, size_t size)
{
- /*
- * XXX: if access_ok, get_user, and put_user handled
- * sig_on_uaccess_err, this could go away.
- */
-
if (!access_ok((void __user *)ptr, size)) {
struct thread_struct *thread = &current->thread;
@@ -120,10 +115,8 @@ static bool write_ok_or_segv(unsigned long ptr, size_t size)
bool emulate_vsyscall(unsigned long error_code,
struct pt_regs *regs, unsigned long address)
{
- struct task_struct *tsk;
unsigned long caller;
int vsyscall_nr, syscall_nr, tmp;
- int prev_sig_on_uaccess_err;
long ret;
unsigned long orig_dx;
@@ -172,8 +165,6 @@ bool emulate_vsyscall(unsigned long error_code,
goto sigsegv;
}
- tsk = current;
-
/*
* Check for access_ok violations and find the syscall nr.
*
@@ -234,12 +225,8 @@ bool emulate_vsyscall(unsigned long error_code,
goto do_ret; /* skip requested */
/*
- * With a real vsyscall, page faults cause SIGSEGV. We want to
- * preserve that behavior to make writing exploits harder.
+ * With a real vsyscall, page faults cause SIGSEGV.
*/
- prev_sig_on_uaccess_err = current->thread.sig_on_uaccess_err;
- current->thread.sig_on_uaccess_err = 1;
-
ret = -EFAULT;
switch (vsyscall_nr) {
case 0:
@@ -262,23 +249,12 @@ bool emulate_vsyscall(unsigned long error_code,
break;
}
- current->thread.sig_on_uaccess_err = prev_sig_on_uaccess_err;
-
check_fault:
if (ret == -EFAULT) {
/* Bad news -- userspace fed a bad pointer to a vsyscall. */
warn_bad_vsyscall(KERN_INFO, regs,
"vsyscall fault (exploit attempt?)");
-
- /*
- * If we failed to generate a signal for any reason,
- * generate one here. (This should be impossible.)
- */
- if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) &&
- !sigismember(&tsk->pending.signal, SIGSEGV)))
- goto sigsegv;
-
- return true; /* Don't emulate the ret. */
+ goto sigsegv;
}
regs->ax = ret;