Commit e04862fd authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Chen Zhongjin
Browse files

uprobes: fix kernel info leak via "[uprobes]" vma 

stable inclusion
from stable-v5.10.227
commit f561b48d633ac2e7d0d667020fc634a96ade33a0
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRDD
CVE: CVE-2024-49975

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f561b48d633ac2e7d0d667020fc634a96ade33a0

--------------------------------

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: default avatarWill Deacon <will@kernel.org>
Fixes: d4b3b638 ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@vger.kernel.org
Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarChen Zhongjin <chenzhongjin@huawei.com>
parent c67d418d

kernel/events/uprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -1497,7 +1497,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) 
	area->xol_mapping.name = "[uprobes]";

	area->xol_mapping.fault = NULL;

	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;