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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id b5-20020aa78705000000b0068ff267f094sm3481738pfo.158.2023.09.28.20.24.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Sep 2023 20:24:36 -0700 (PDT) From: Kees Cook To: Eric Biederman Cc: Kees Cook , Alexander Viro , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Sebastian Ott , =?utf-8?q?Thomas_Wei?= =?utf-8?q?=C3=9Fschuh?= , Pedro Falcato , Andrew Morton , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v4 4/6] binfmt_elf: Use elf_load() for library Date: Thu, 28 Sep 2023 20:24:32 -0700 Message-Id: <20230929032435.2391507-4-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230929031716.it.155-kees@kernel.org> References: <20230929031716.it.155-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1627; i=keescook@chromium.org; h=from:subject; bh=HDRWJgiZi2B41NjfcoHun/GXVPB8PhMH+K8nRgD/QEY=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlFkNyd7onj53UAnvTrNuqjrOoqdzlhhnL6T0n4 waDipxrCuyJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZRZDcgAKCRCJcvTf3G3A JgqhEACQaxzh9TUbPcDbZo8niTtocmDdmljr+QUAo/kUcZsO7WwVGlruTUeAl3DsFH2PvI/7f8q 6Gzf2F516CRNsoFBvkxeJHFWa21p4CjiRwEYH+rdFGIQwe4ZXPrdSrcJhWVB35JNjqR8CK/aRK2 NAJeh7WuuaTnpcDhFmPiXWQuRt1noAczm74SRZU8IZ06ucQ49FNFgl7FPCGA0RLuWRQDEc4zXaQ BQktUi2h0of64YlxMdZfk+SQMGz2lOqO7a3F8Zy9PazbSnHb5k2NrkreHnNxtncdID9uE6SiKy+ JVJ8/BMveYU1W8I+asdhp8xe2CV19g1Qmlq4ZVCoeGxeV9OtFE+c8gjwaTlFdRjzRgfVqvqVmtp OYM3ExS5b6+tEeavoEpUw88foXpj9yoZLMwL8pVfsXc2FYIlPsrtaFfUyacQhttqevffosf/oUf bksChMr+i07cgy1L/yGOx/6wCfvU8HTwH+VMXDpSSowba7S7GbBmvxw9EtoVWjqJAGNdtQ6FvJZ 6SXLe7ag42PtcuMWe8C14GuF1yYIcvu/o/vpy24R3zfZUovoJAGPuns5yKBok4/GV2c31zPoB/p 5ZXXOtl28un+F7p/qF9lnnk6I8GbyO4YgCPqLeXph77PUUZfI4r38oOBt9/p+hKk0yQ+7nD6eH+ 8MpI/toIRLPKXkg== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net While load_elf_library() is a libc5-ism, we can still replace most of its contents with elf_load() as well, further simplifying the code. Cc: Alexander Viro Cc: Christian Brauner Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Suggested-by: Eric Biederman Signed-off-by: Kees Cook --- fs/binfmt_elf.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index db47cb802f89..f8b4747f87ed 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1351,30 +1351,15 @@ static int load_elf_library(struct file *file) eppnt++; /* Now use mmap to map the library into memory. */ - error = vm_mmap(file, - ELF_PAGESTART(eppnt->p_vaddr), - (eppnt->p_filesz + - ELF_PAGEOFFSET(eppnt->p_vaddr)), + error = elf_load(file, ELF_PAGESTART(eppnt->p_vaddr), + eppnt, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_FIXED_NOREPLACE | MAP_PRIVATE, - (eppnt->p_offset - - ELF_PAGEOFFSET(eppnt->p_vaddr))); - if (error != ELF_PAGESTART(eppnt->p_vaddr)) - goto out_free_ph; + 0); - elf_bss = eppnt->p_vaddr + eppnt->p_filesz; - if (padzero(elf_bss)) { - error = -EFAULT; + if (error != ELF_PAGESTART(eppnt->p_vaddr)) goto out_free_ph; - } - len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); - bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); - if (bss > len) { - error = vm_brk(len, bss - len); - if (error) - goto out_free_ph; - } error = 0; out_free_ph: