The patch below does not apply to the 6.11-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 stable@vger.kernel.org.

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-6.11.y git checkout FETCH_HEAD git cherry-pick -x 34820304cc2cd1804ee1f8f3504ec77813d29c8e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024100757-gambling-blurry-b71e@gregkh' --subject-prefix 'PATCH 6.11.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")

thanks,

greg k-h

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

From 34820304cc2cd1804ee1f8f3504ec77813d29c8e Mon Sep 17 00:00:00 2001 From: Oleg Nesterov oleg@redhat.com 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.

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

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2ec796e2f055..4b52cb2ae6d6 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -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;