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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id v7-20020a170902b7c700b001c61073b064sm5974160plz.69.2023.09.26.20.42.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Sep 2023 20:42:24 -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=20Wei=C3=9Fschuh?= , Pedro Falcato , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v3 2/4] binfmt_elf: elf_bss no longer used by load_elf_binary() Date: Tue, 26 Sep 2023 20:42:19 -0700 Message-Id: <20230927034223.986157-2-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230927033634.make.602-kees@kernel.org> References: <20230927033634.make.602-kees@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1738; i=keescook@chromium.org; h=from:subject; bh=G8gKivjP+bPsGdacm75CduzZVarN6sAt0dfrtCVUjtY=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlE6Sd2BuLhX7iIAkgIu+LW3P3r4pxnZlwRaDRf vA/0AICBj2JAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZROknQAKCRCJcvTf3G3A JoZiEACxnnqWBzMIIDewc78beSt5xMPBmGmN6i2luWvAqAMFgVuNI0nDLE57tnMWit7yDj2XgJ1 2Z/pa68XIcntr/l4Ox2lUHBpmeW82kMxXbte18Ecfkifetz5bSTNhT4eqz9iInkevtzRWO3uUpq i3Sjs/gANX1ErFrzlbJdGorFoQ2WChDbSXKcGCifcF+7ByszsUMc7ciRkTfJ+c69ymHfkIjFnB4 NABq4TtLUWJgQ4fWWHfAXP7ibJqTV+vue/6haJy4EBtrPblhUpyXmaPHPlLFqfB4NWp67PspCGn Xt+4d8whIqgJJO12woWoD2kad16SwfEWwy6rtb5glKxP4P8lwFkwUY2npYvmLb7oLp/JOBGWtT4 zN8stmcyYoHO5JH1fxDZ/M4IbnvhDjIyT/v4bcz2Sn/t26aRdaLx2dvl1fz3GLavqQm1IhRhQ+f XxYEJIe0C5lZ5EdXJrERty9WadxoFIpFZuQtqKSIfGNDtWQIQ1fwZPbObiOfsYvT6LcbQLKMUG1 /xXJ+v8+u3jW+HTFnzZ+EE7ig4RRSprVCTd5QEzX4RbC8KXboi2yMozBdmUhOTOlkUJSU/uUZ1+ VZHcMo6rE0t3wu84BkMjvDVBAPXSGtNLDJ9xoujVrtMltIzQDhdxPz2ce74LXQ2WEx1wn991e8y t1zbNpVW5qc63Kw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" With the BSS handled generically via the new filesz/memsz mismatch handling logic in elf_load(), elf_bss no longer needs to be tracked. Drop the variable. Cc: Eric Biederman 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 | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 2a615f476e44..0214d5a949fc 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -854,7 +854,7 @@ static int load_elf_binary(struct linux_binprm *bprm) unsigned long error; struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata =3D NULL; struct elf_phdr *elf_property_phdata =3D NULL; - unsigned long elf_bss, elf_brk; + unsigned long elf_brk; int retval, i; unsigned long elf_entry; unsigned long e_entry; @@ -1045,7 +1045,6 @@ static int load_elf_binary(struct linux_binprm *bprm) if (retval < 0) goto out_free_dentry; =20 - elf_bss =3D 0; elf_brk =3D 0; =20 start_code =3D ~0UL; @@ -1208,8 +1207,6 @@ static int load_elf_binary(struct linux_binprm *bprm) =20 k =3D elf_ppnt->p_vaddr + elf_ppnt->p_filesz; =20 - if (k > elf_bss) - elf_bss =3D k; if ((elf_ppnt->p_flags & PF_X) && end_code < k) end_code =3D k; if (end_data < k) @@ -1221,7 +1218,6 @@ static int load_elf_binary(struct linux_binprm *bprm) =20 e_entry =3D elf_ex->e_entry + load_bias; phdr_addr +=3D load_bias; - elf_bss +=3D load_bias; elf_brk +=3D load_bias; start_code +=3D load_bias; end_code +=3D load_bias; --=20 2.34.1