diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2024-10-07 20:46:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-10 13:01:09 +0300 |
| commit | 2aa45f43709ba2082917bd2973d02687075b6eee (patch) | |
| tree | 1e6a1aab2a91a5e6e2c72842ff132bf15204160a | |
| parent | 94f87d63613aaa90523ec260d5749c572a2c13d1 (diff) | |
| download | linux-2aa45f43709ba2082917bd2973d02687075b6eee.tar.xz | |
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/events/uprobes.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 28c678c8daef..3dd1f1464364 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1491,7 +1491,7 @@ 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; |