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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------------------------------------------------------
From: Yafang Shao <laoar.shao@xxxxxxxxx>
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@xxxxxxxxx
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@xxxxxxxxxxxxxx/ [0]
Acked-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
Cc: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>
Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Cc: Alejandro Colomar <alx@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Eric Paris <eparis@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Justin Stitt <justinstitt@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Matus Jokay <matus.jokay@xxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Quentin Monnet <qmo@xxxxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxx 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
