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From: Jisheng Zhang <jszhang@kernel.org>
To: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 1/4] riscv: process: fix kernel info leakage
Date: Mon,  3 Oct 2022 18:29:18 +0800	[thread overview]
Message-ID: <20221003102921.3973-2-jszhang@kernel.org> (raw)
In-Reply-To: <20221003102921.3973-1-jszhang@kernel.org>

thread_struct's s[12] may contain random kernel memory content, which
may be finally leaked to userspace. This is a security hole. Fix it
by clearing the s[12] array in thread_struct when fork.

As for kthread case, it's better to clear the s[12] array as well.

Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 arch/riscv/kernel/process.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index ceb9ebab6558..52002d54b163 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -164,6 +164,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);
 
+	memset(&p->thread.s, 0, sizeof(p->thread.s));
+
 	/* p->thread holds context to be restored by __switch_to() */
 	if (unlikely(args->fn)) {
 		/* Kernel thread */
-- 
2.37.2


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WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <jszhang@kernel.org>
To: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 1/4] riscv: process: fix kernel info leakage
Date: Mon,  3 Oct 2022 18:29:18 +0800	[thread overview]
Message-ID: <20221003102921.3973-2-jszhang@kernel.org> (raw)
In-Reply-To: <20221003102921.3973-1-jszhang@kernel.org>

thread_struct's s[12] may contain random kernel memory content, which
may be finally leaked to userspace. This is a security hole. Fix it
by clearing the s[12] array in thread_struct when fork.

As for kthread case, it's better to clear the s[12] array as well.

Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 arch/riscv/kernel/process.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index ceb9ebab6558..52002d54b163 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -164,6 +164,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 	unsigned long tls = args->tls;
 	struct pt_regs *childregs = task_pt_regs(p);
 
+	memset(&p->thread.s, 0, sizeof(p->thread.s));
+
 	/* p->thread holds context to be restored by __switch_to() */
 	if (unlikely(args->fn)) {
 		/* Kernel thread */
-- 
2.37.2


  reply	other threads:[~2022-10-03 10:39 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-03 10:29 [PATCH v3 0/4] riscv: entry: further clean up and VMAP_STACK fix Jisheng Zhang
2022-10-03 10:29 ` Jisheng Zhang
2022-10-03 10:29 ` Jisheng Zhang [this message]
2022-10-03 10:29   ` [PATCH v3 1/4] riscv: process: fix kernel info leakage Jisheng Zhang
2022-10-04 16:04   ` Guo Ren
2022-10-04 16:04     ` Guo Ren
2022-10-03 10:29 ` [PATCH v3 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Jisheng Zhang
2022-10-03 10:29   ` Jisheng Zhang
2022-10-03 10:29 ` [PATCH v3 3/4] riscv: fix race when vmap stack overflow and remove shadow_stack Jisheng Zhang
2022-10-03 10:29   ` Jisheng Zhang
2022-10-03 10:29 ` [PATCH v3 4/4] riscv: entry: consolidate general regs saving/restoring Jisheng Zhang
2022-10-03 10:29   ` Jisheng Zhang
2022-10-04 16:03   ` Guo Ren
2022-10-04 16:03     ` Guo Ren

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