+ security-replace-memcpy-with-get_task_comm.patch added to mm-nonmm-unstable branch

+ security-replace-memcpy-with-get_task_comm.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: security: replace memcpy() with get_task_comm()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     security-replace-memcpy-with-get_task_comm.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/security-replace-memcpy-with-get_task_comm.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Yafang Shao <laoar.shao@gmail.com>
Subject: security: replace memcpy() with get_task_comm()
Date: Mon, 7 Oct 2024 22:49:07 +0800

Quoted from Linus [0]:

  selinux never wanted a lock, and never wanted any kind of *consistent*
  result, it just wanted a *stable* result.

Using get_task_comm() to read the task comm ensures that the name is
always NUL-terminated, regardless of the source string. This approach also
facilitates future extensions to the task comm.

Link: https://lkml.kernel.org/r/20241007144911.27693-4-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com/ [0]
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Alejandro Colomar <alx@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matus Jokay <matus.jokay@stuba.sk>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 security/lsm_audit.c         |    4 ++--
 security/selinux/selinuxfs.c |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

--- a/security/lsm_audit.c~security-replace-memcpy-with-get_task_comm
+++ a/security/lsm_audit.c
@@ -207,7 +207,7 @@ static void dump_common_audit_data(struc
 	BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);
 
 	audit_log_format(ab, " pid=%d comm=", task_tgid_nr(current));
-	audit_log_untrustedstring(ab, memcpy(comm, current->comm, sizeof(comm)));
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
 
 	switch (a->type) {
 	case LSM_AUDIT_DATA_NONE:
@@ -302,7 +302,7 @@ static void dump_common_audit_data(struc
 				char comm[sizeof(tsk->comm)];
 				audit_log_format(ab, " opid=%d ocomm=", pid);
 				audit_log_untrustedstring(ab,
-				    memcpy(comm, tsk->comm, sizeof(comm)));
+				    get_task_comm(comm, tsk));
 			}
 		}
 		break;
--- a/security/selinux/selinuxfs.c~security-replace-memcpy-with-get_task_comm
+++ a/security/selinux/selinuxfs.c
@@ -708,7 +708,7 @@ static ssize_t sel_write_checkreqprot(st
 	if (new_value) {
 		char comm[sizeof(current->comm)];
 
-		memcpy(comm, current->comm, sizeof(comm));
+		strscpy(comm, current->comm);
 		pr_err("SELinux: %s (%d) set checkreqprot to 1. This is no longer supported.\n",
 		       comm, current->pid);
 	}
_

Patches currently in -mm which might be from laoar.shao@gmail.com are

get-rid-of-__get_task_comm.patch
auditsc-replace-memcpy-with-strscpy.patch
security-replace-memcpy-with-get_task_comm.patch
bpftool-ensure-task-comm-is-always-nul-terminated.patch
mm-util-fix-possible-race-condition-in-kstrdup.patch
mm-util-deduplicate-code-in-kstrdupkstrndupkmemdup_nul.patch
drm-replace-strcpy-with-strscpy.patch