From mboxrd@z Thu Jan 1 00:00:00 1970 From: andreyknvl@google.com (Andrey Konovalov) Date: Wed, 18 Apr 2018 20:53:14 +0200 Subject: [PATCH 5/6] lib, arm64: untag addrs passed to strncpy_from_user and strnlen_user In-Reply-To: References: Message-ID: <82ccccd82c350f9243fc4e1d377cdad9bf23809c.1524077494.git.andreyknvl@google.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org strncpy_from_user and strnlen_user accept user addresses as arguments, and do not go through the same path as copy_from_user and others, so here we need to separately handle the case of tagged user addresses as well. Untag user pointers passed to these functions. Signed-off-by: Andrey Konovalov --- lib/strncpy_from_user.c | 2 ++ lib/strnlen_user.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index b53e1b5d80f4..97467cd2bc59 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -106,6 +106,8 @@ long strncpy_from_user(char *dst, const char __user *src, long count) if (unlikely(count <= 0)) return 0; + src = untagged_addr(src); + max_addr = user_addr_max(); src_addr = (unsigned long)src; if (likely(src_addr < max_addr)) { diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 60d0bbda8f5e..8b5f56466e00 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -108,6 +108,8 @@ long strnlen_user(const char __user *str, long count) if (unlikely(count <= 0)) return 0; + str = untagged_addr(str); + max_addr = user_addr_max(); src_addr = (unsigned long)str; if (likely(src_addr < max_addr)) { -- 2.17.0.484.g0c8726318c-goog