From 7d063d6544b9a2686c6ea5929abf1612d394bd41 Mon Sep 17 00:00:00 2001 From: Rudi Heitbaum Date: Fri, 14 Jul 2023 08:41:36 +0000 Subject: [PATCH] shm: use MFD_NOEXEC_SEAL for shared memory ref: https://lore.kernel.org/lkml/20221207154939.2532830-4-jeffxu@google.com/ The new MFD_NOEXEC_SEAL and MFD_EXEC flags allows application to set executable bit at creation time (memfd_create). When MFD_NOEXEC_SEAL is set, memfd is created without executable bit (mode:0666), and sealed with F_SEAL_EXEC, so it can't be chmod to be executable (mode: 0777) after creation. when MFD_EXEC flag is set, memfd is created with executable bit (mode:0777), this is the same as the old behavior of memfd_create. Signed-off-by: Rudi Heitbaum Part-of: --- src/pulsecore/memfd-wrappers.h | 4 ++++ src/pulsecore/shm.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/src/pulsecore/memfd-wrappers.h b/src/pulsecore/memfd-wrappers.h index c7aadfd3c..4708751ad 100644 --- a/src/pulsecore/memfd-wrappers.h +++ b/src/pulsecore/memfd-wrappers.h @@ -66,4 +66,8 @@ static inline int memfd_create(const char *name, unsigned int flags) { #endif /* HAVE_MEMFD && !HAVE_MEMFD_CREATE */ +#ifndef MFD_NOEXEC_SEAL +#define MFD_NOEXEC_SEAL 0x0008U +#endif + #endif diff --git a/src/pulsecore/shm.c b/src/pulsecore/shm.c index ff54dcb59..4247b0921 100644 --- a/src/pulsecore/shm.c +++ b/src/pulsecore/shm.c @@ -164,7 +164,7 @@ static int sharedmem_create(pa_shm *m, pa_mem_type_t type, size_t size, mode_t m #endif #ifdef HAVE_MEMFD case PA_MEM_TYPE_SHARED_MEMFD: - fd = memfd_create("pulseaudio", MFD_ALLOW_SEALING|MFD_CLOEXEC); + fd = memfd_create("pulseaudio", MFD_ALLOW_SEALING|MFD_CLOEXEC|MFD_NOEXEC_SEAL); break; #endif default: