From c8ddc8cc40e6380762c5a22886554b263ae8a212 Mon Sep 17 00:00:00 2001 From: Todd Kjos Date: Tue, 19 Mar 2019 09:53:01 -0700 Subject: [PATCH] FROMGIT: binder: fix BUG_ON found by selinux-testsuite The selinux-testsuite found an issue resulting in a BUG_ON() where a conditional relied on a size_t going negative when checking the validity of a buffer offset. (cherry picked from commit 5997da82145bb7c9a56d834894cb81f81f219344 git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-linus) Bug: 67668716 Bug: 129349786 Change-Id: Ib3b408717141deadddcb6b95ad98c0b97d9d98ea Fixes: 7a67a39320df ("binder: add function to copy binder object from buffer") Reported-by: Paul Moore Tested-by: Paul Moore Signed-off-by: Todd Kjos --- drivers/android/binder.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 50b582f510c5..8898a2298e54 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2240,7 +2240,8 @@ static size_t binder_get_object(struct binder_proc *proc, size_t object_size = 0; read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset); - if (read_size < sizeof(*hdr) || !IS_ALIGNED(offset, sizeof(u32))) + if (offset > buffer->data_size || read_size < sizeof(*hdr) || + !IS_ALIGNED(offset, sizeof(u32))) return 0; binder_alloc_copy_from_buffer(&proc->alloc, object, buffer, offset, read_size);