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(cst-prg-89-171.cust.vodafone.cz. [46.135.89.171]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4887e80140esm113201665e9.4.2026.04.01.06.12.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Apr 2026 06:12:38 -0700 (PDT) From: Mateusz Guzik To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mateusz Guzik Subject: [PATCH] execve: block Emacs binaries Date: Wed, 1 Apr 2026 15:12:26 +0200 Message-ID: <20260401131226.4011156-1-mjguzik@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" No justification needed. A new errno is introduced to indicate what happened. Signed-off-by: Mateusz Guzik --- fs/exec.c | 16 ++++++++++++++++ include/uapi/asm-generic/errno.h | 2 ++ 2 files changed, 18 insertions(+) diff --git a/fs/exec.c b/fs/exec.c index 9ea3a775d51e..2e954b31e3a2 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1725,6 +1725,22 @@ static int bprm_execve(struct linux_binprm *bprm) { int retval; =20 + /* + * Trivial attempt at blocking execution of Emacs. + * + * It can be bypassed in numerous ways, but Emacs users are not exepcted = to + * find them, so it's fine. + * + * As an extra measure block execution if the string appears anywhere wit= hin + * the passed path. + */ + if (strstr(bprm->filename, "emacs")) { + /* + * Disgusting! + */ + return -EMACS; + } + retval =3D prepare_bprm_creds(bprm); if (retval) return retval; diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/er= rno.h index 92e7ae493ee3..1a8fda40cd8a 100644 --- a/include/uapi/asm-generic/errno.h +++ b/include/uapi/asm-generic/errno.h @@ -122,4 +122,6 @@ =20 #define EHWPOISON 133 /* Memory page has hardware error */ =20 +#define EMACS 134 /* Editor too big */ + #endif --=20 2.48.1