From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Subject: [RFC v2 07/10] landlock: Add errno check Date: Thu, 25 Aug 2016 12:32:42 +0200 Message-ID: <1472121165-29071-8-git-send-email-mic@digikod.net> References: <1472121165-29071-1-git-send-email-mic@digikod.net> Reply-To: kernel-hardening@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: List-Post: List-Help: List-Unsubscribe: List-Subscribe: In-Reply-To: <1472121165-29071-1-git-send-email-mic@digikod.net> To: linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , Alexei Starovoitov , Andy Lutomirski , Arnd Bergmann , Casey Schaufler , Daniel Borkmann , Daniel Mack , David Drysdale , "David S . Miller" , Elena Reshetova , James Morris , Kees Cook , Paul Moore , Sargun Dhillon , "Serge E . Hallyn" , Will Drewry , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, netdev@vger.kernel.org List-Id: linux-api@vger.kernel.org Add a max errno value. This is not strictly needed but should improve reliability. Signed-off-by: Mickaël Salaün Cc: Arnd Bergmann Cc: Serge E. Hallyn Cc: James Morris Cc: Kees Cook --- include/uapi/asm-generic/errno-base.h | 1 + security/landlock/lsm.c | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/include/uapi/asm-generic/errno-base.h b/include/uapi/asm-generic/errno-base.h index 65115978510f..43407a403e72 100644 --- a/include/uapi/asm-generic/errno-base.h +++ b/include/uapi/asm-generic/errno-base.h @@ -35,5 +35,6 @@ #define EPIPE 32 /* Broken pipe */ #define EDOM 33 /* Math argument out of domain of func */ #define ERANGE 34 /* Math result not representable */ +#define _ERRNO_LAST ERANGE #endif diff --git a/security/landlock/lsm.c b/security/landlock/lsm.c index aa9d4a64826e..322309068066 100644 --- a/security/landlock/lsm.c +++ b/security/landlock/lsm.c @@ -11,7 +11,6 @@ #include #include /* enum bpf_reg_type, struct landlock_data */ #include -#include /* MAX_ERRNO */ #include /* struct bpf_prog, BPF_PROG_RUN() */ #include /* FIELD_SIZEOF() */ #include @@ -104,8 +103,9 @@ static int landlock_run_prog(__u64 args[6]) } } if (!ret) { - if (cur_ret > MAX_ERRNO) - ret = MAX_ERRNO; + /* check errno to not mess with kernel code */ + if (cur_ret > _ERRNO_LAST) + ret = EPERM; else ret = cur_ret; } -- 2.8.1