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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] riscv: process: fix kernel info leakage
Date: Sat, 29 Oct 2022 19:34:50 +0800	[thread overview]
Message-ID: <20221029113450.4027-1-jszhang@kernel.org> (raw)

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>
---

Previously, it's one of the series of "riscv: entry: further clean up
and VMAP_STACK fix". This is a fix, so I move it out of the series and
send it separately

 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


WARNING: multiple messages have this Message-ID
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] riscv: process: fix kernel info leakage
Date: Sat, 29 Oct 2022 19:34:50 +0800	[thread overview]
Message-ID: <20221029113450.4027-1-jszhang@kernel.org> (raw)

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>
---

Previously, it's one of the series of "riscv: entry: further clean up
and VMAP_STACK fix". This is a fix, so I move it out of the series and
send it separately

 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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             reply	other threads:[~2022-10-29 11:44 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-29 11:34 Jisheng Zhang [this message]
2022-10-29 11:34 ` [PATCH] riscv: process: fix kernel info leakage Jisheng Zhang
2022-10-30  0:03 ` Guo Ren
2022-10-30  0:03   ` Guo Ren
2022-10-31 19:14 ` Conor Dooley
2022-10-31 19:14   ` Conor Dooley
2022-11-10 22:45 ` Palmer Dabbelt
2022-11-10 22:45   ` Palmer Dabbelt
2022-11-10 22:50 ` patchwork-bot+linux-riscv
2022-11-10 22:50   ` patchwork-bot+linux-riscv

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