From ab3765a050f7bea942f114d07278e1775e38199b Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Sun, 23 Jun 2019 11:35:04 +0800 Subject: x86/speculation/mds: Eliminate leaks by trace_hardirqs_on() Move mds_idle_clear_cpu_buffers() after trace_hardirqs_on() to ensure all store buffer entries are flushed. Signed-off-by: Zhenzhong Duan Signed-off-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: jgross@suse.com Cc: ndesaulniers@google.com Cc: gregkh@linuxfoundation.org Link: https://lkml.kernel.org/r/1561260904-29669-2-git-send-email-zhenzhong.duan@oracle.com --- arch/x86/include/asm/mwait.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h index eb0f80ce8524..e28f8b723b5c 100644 --- a/arch/x86/include/asm/mwait.h +++ b/arch/x86/include/asm/mwait.h @@ -86,9 +86,9 @@ static inline void __mwaitx(unsigned long eax, unsigned long ebx, static inline void __sti_mwait(unsigned long eax, unsigned long ecx) { - mds_idle_clear_cpu_buffers(); - trace_hardirqs_on(); + + mds_idle_clear_cpu_buffers(); /* "mwait %eax, %ecx;" */ asm volatile("sti; .byte 0x0f, 0x01, 0xc9;" :: "a" (eax), "c" (ecx)); -- cgit v1.2.3 From 31a2fbb390fee4231281b939e1979e810f945415 Mon Sep 17 00:00:00 2001 From: Dianzhang Chen Date: Tue, 25 Jun 2019 23:30:17 +0800 Subject: x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg() The index to access the threads ptrace_bps is controlled by userspace via syscall: sys_ptrace(), hence leading to a potential exploitation of the Spectre variant 1 vulnerability. The index can be controlled from: ptrace -> arch_ptrace -> ptrace_get_debugreg. Fix this by sanitizing the user supplied index before using it access thread->ptrace_bps. Signed-off-by: Dianzhang Chen Signed-off-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1561476617-3759-1-git-send-email-dianzhangchen0@gmail.com --- arch/x86/kernel/ptrace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index a166c960bc9e..cbac64659dc4 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -643,9 +644,11 @@ 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) { - struct perf_event *bp = thread->ptrace_bps[n]; + index = array_index_nospec(index, HBP_NUM); + struct perf_event *bp = thread->ptrace_bps[index]; if (bp) val = bp->hw.info.address; -- cgit v1.2.3 From 993773d11d45c90cb1c6481c2638c3d9f092ea5b Mon Sep 17 00:00:00 2001 From: Dianzhang Chen Date: Wed, 26 Jun 2019 12:50:30 +0800 Subject: x86/tls: Fix possible spectre-v1 in do_get_thread_area() The index to access the threads tls array is controlled by userspace via syscall: sys_ptrace(), hence leading to a potential exploitation of the Spectre variant 1 vulnerability. The index can be controlled from: ptrace -> arch_ptrace -> do_get_thread_area. Fix this by sanitizing the user supplied index before using it to access the p->thread.tls_array. Signed-off-by: Dianzhang Chen Signed-off-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1561524630-3642-1-git-send-email-dianzhangchen0@gmail.com --- arch/x86/kernel/tls.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c index a5b802a12212..71d3fef1edc9 100644 --- a/arch/x86/kernel/tls.c +++ b/arch/x86/kernel/tls.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include @@ -220,6 +221,7 @@ int do_get_thread_area(struct task_struct *p, int idx, struct user_desc __user *u_info) { struct user_desc info; + int index; if (idx == -1 && get_user(idx, &u_info->entry_number)) return -EFAULT; @@ -227,8 +229,11 @@ int do_get_thread_area(struct task_struct *p, int idx, if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) return -EINVAL; - fill_user_desc(&info, idx, - &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]); + index = idx - GDT_ENTRY_TLS_MIN; + index = array_index_nospec(index, + GDT_ENTRY_TLS_MAX - GDT_ENTRY_TLS_MIN + 1); + + fill_user_desc(&info, idx, &p->thread.tls_array[index]); if (copy_to_user(u_info, &info, sizeof(info))) return -EFAULT; -- cgit v1.2.3