Re: FAILED: patch "[PATCH] uprobes: fix kernel info leak via "[uprobes]" vma" failed to apply to 6.11-stable tree

[Oleg Nesterov <oleg@redhat.com>]

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Hi Greg,

On 10/07, gregkh@linuxfoundation.org wrote:
>
> The patch below does not apply to the 6.11-stable tree.

Please see the attached patch. For v6.11 and the previous versions.

Oleg.

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From 112e436ce71b8630f50b6ac17db52999255cd3fe Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Mon, 7 Oct 2024 19:46:01 +0200
Subject: [PATCH -stable] uprobes: fix kernel info leak via "[uprobes]" vma

commit 34820304cc2cd1804ee1f8f3504ec77813d29c8e upstream.

xol_add_vma() maps the uninitialized page allocated by __create_xol_area()
into userspace. On some architectures (x86) this memory is readable even
without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ,
although this doesn't really matter, debugger can read this memory anyway.

Link: https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/

Reported-by: Will Deacon <will@kernel.org>
Fixes: d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/events/uprobes.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 50d7949be2b1..1650c05c9dc7 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1500,7 +1500,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 
 	area->xol_mapping.name = "[uprobes]";
 	area->xol_mapping.pages = area->pages;
-	area->pages[0] = alloc_page(GFP_HIGHUSER);
+	area->pages[0] = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
 	if (!area->pages[0])
 		goto free_bitmap;
 	area->pages[1] = NULL;
-- 
2.25.1.362.g51ebf55