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FAILED: patch "[PATCH] uprobes: fix kernel info leak via "[uprobes]" vma" failed to apply to 6.6-stable tree

PATCH [email protected] 1 participant 1 message Oct 7, 2024

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The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 34820304cc2cd1804ee1f8f3504ec77813d29c8e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024100758-mossy-data-89d8@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

34820304cc2c ("uprobes: fix kernel info leak via "[uprobes]" vma") 2abbcc099ec6 ("uprobes: turn xol_area->pages[2] into xol_area->page") 6d27a31ef195 ("uprobes: introduce the global struct vm_special_mapping xol_mapping") ff474a78cef5 ("uprobe: Add uretprobe syscall to speed up return probe") 1713b63a07a2 ("x86/shstk: Make return uprobe work with shadow stack")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 34820304cc2cd1804ee1f8f3504ec77813d29c8e Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <[email protected]>
Date: Sun, 29 Sep 2024 18:20:47 +0200
Subject: [PATCH] uprobes: fix kernel info leak via "[uprobes]" vma

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.

Fixes d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use")
kernel/events/uprobes.c +1 -1
index 2ec796e2f055..4b52cb2ae6d6 100644
@@ -1545,7 +1545,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 	if (!area->bitmap)
 		goto free_area;
 
-	area->page = alloc_page(GFP_HIGHUSER);
+	area->page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
 	if (!area->page)
 		goto free_bitmap;