From: Peilin Ye <yepeilin.cs@gmail.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org,
Peilin Ye <yepeilin.cs@gmail.com>,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: [Linux-kernel-mentees] [PATCH] ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info()
Date: Mon, 27 Jul 2020 17:36:44 -0400 [thread overview]
Message-ID: <20200727213644.328662-1-yepeilin.cs@gmail.com> (raw)
ptrace_get_syscall_info() is copying uninitialized stack memory to
userspace due to the compiler not initializing holes in statically
allocated structures. Fix it by initializing `info` with memset().
Cc: stable@vger.kernel.org
Fixes: 201766a20e30 ("ptrace: add PTRACE_GET_SYSCALL_INFO request")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
kernel/ptrace.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 43d6179508d6..e48d05b765b5 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -960,15 +960,17 @@ ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
void __user *datavp)
{
struct pt_regs *regs = task_pt_regs(child);
- struct ptrace_syscall_info info = {
- .op = PTRACE_SYSCALL_INFO_NONE,
- .arch = syscall_get_arch(child),
- .instruction_pointer = instruction_pointer(regs),
- .stack_pointer = user_stack_pointer(regs),
- };
+ struct ptrace_syscall_info info;
unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
unsigned long write_size;
+ memset(&info, 0, sizeof(info));
+
+ info.op = PTRACE_SYSCALL_INFO_NONE;
+ info.arch = syscall_get_arch(child);
+ info.instruction_pointer = instruction_pointer(regs);
+ info.stack_pointer = user_stack_pointer(regs);
+
/*
* This does not need lock_task_sighand() to access
* child->last_siginfo because ptrace_freeze_traced()
--
2.25.1
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next reply other threads:[~2020-07-27 21:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 21:36 Peilin Ye [this message]
2020-08-01 0:21 ` [Linux-kernel-mentees] [PATCH] ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info() Dmitry V. Levin
2020-08-01 1:28 ` Peilin Ye
2020-08-01 2:08 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-08-01 11:06 ` Dmitry V. Levin
2020-08-01 15:09 ` Peilin Ye
2020-08-01 15:20 ` [Linux-kernel-mentees] [PATCH v3] " Peilin Ye
2020-08-01 16:08 ` Dmitry V. Levin
2020-08-01 20:10 ` Christian Brauner
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