The macro unsafe_put_sigmask() only handles the first 64 bits of the
sigmask_t, which works today. However, if the definition of the
sigset_t structure ever changed, this would fail to setup/restore the
signal stack properly and likely corrupt the sigset. This patch
updates unsafe_put_sigmask() to correctly save all the fields in the
sigmask_t struct, and adds unsafe_put_compat_sigmask() to handle the
compat_sigset_t cases.
Signed-off-by: Walt Drummond <w...@drummond.us>
---
arch/x86/kernel/signal.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index be0d7d4152ec..4d5134b4bb5f 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -203,11 +203,18 @@ do {
\
goto label; \
} while(0);
-#define unsafe_put_sigmask(set, frame, label) \
+#define unsafe_put_compat_sigmask(set, frame, label) \
unsafe_put_user(*(__u64 *)(set), \
(__u64 __user *)&(frame)->uc.uc_sigmask, \
label)
+#define unsafe_put_sigmask(set, frame, label) \
+do { \
+ int i; \
+ for (i = 0; i < _NSIG_WORDS; i++) \
+ unsafe_put_user((set)->sig[i], &(frame)->uc.uc_sigmask.sig[i],
label); \
+} while(0);
+
/*
* Set up a signal frame.
*/
@@ -566,7 +573,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
restorer = ksig->ka.sa.sa_restorer;
unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode,
Efault);
unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
- unsafe_put_sigmask(set, frame, Efault);
+ unsafe_put_compat_sigmask(set, frame, Efault);
user_access_end();
if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
@@ -643,7 +650,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
- if (__get_user(*(__u64 *)&set, (__u64 __user *)&frame->uc.uc_sigmask))
+ if (copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(sigset_t)))
goto badframe;
if (__get_user(uc_flags, &frame->uc.uc_flags))
goto badframe;
--
2.27.0
