Home Home > GIT Browse
diff options
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-04 12:27:18 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-09-06 10:18:17 +0200
commit61263fbe574b0b74c50552983bdcc2bb9a409b1e (patch)
parent8c0932cd8197d290195dc281ff6534e13d9d97e8 (diff)
x86/ptrace: fix up botched merge of spectrev1 fix
I incorrectly merged commit 31a2fbb390fe ("x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()") when backporting it, as was graciously pointed out at https://grsecurity.net/teardown_of_a_failed_linux_lts_spectre_fix.php Resolve the upstream difference with the stable kernel merge to properly protect things. Reported-by: Brad Spengler <spender@grsecurity.net> Cc: Dianzhang Chen <dianzhangchen0@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <bp@alien8.de> Cc: <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 1ca929767a1b..0b6d27dfc234 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -698,11 +698,10 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
struct thread_struct *thread = &tsk->thread;
unsigned long val = 0;
- int index = n;
if (n < HBP_NUM) {
+ int index = array_index_nospec(n, HBP_NUM);
struct perf_event *bp = thread->ptrace_bps[index];
- index = array_index_nospec(index, HBP_NUM);
if (bp)
val = bp->hw.info.address;