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| author | Oleg Nesterov <oleg@redhat.com> | 2024-10-07 19:46:01 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-10 11:58:02 +0200 |
| commit | 5b981d8335e18aef7908a068529a3287258ff6d8 (patch) | |
| tree | 04657ef8f735e77e6cbb874f4e0b9b2db572550a | |
| parent | 24f7989ed2e1b56d8a2661af9e5e41c4c158769f (diff) | |
| download | linux-rpi-5b981d8335e18aef7908a068529a3287258ff6d8.tar.gz linux-rpi-5b981d8335e18aef7908a068529a3287258ff6d8.tar.bz2 linux-rpi-5b981d8335e18aef7908a068529a3287258ff6d8.zip | |
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 6876b7f152b1..6dac0b579821 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; |