linux-stable/fs/proc
Yafang Shao 4cc0473d77 get rid of __get_task_comm()
Patch series "Improve the copy of task comm", v8.

Using {memcpy,strncpy,strcpy,kstrdup} to copy the task comm relies on the
length of task comm.  Changes in the task comm could result in a
destination string that is overflow.  Therefore, we should explicitly
ensure the destination string is always NUL-terminated, regardless of the
task comm.  This approach will facilitate future extensions to the task
comm.

As suggested by Linus [0], we can identify all relevant code with the
following git grep command:

  git grep 'memcpy.*->comm\>'
  git grep 'kstrdup.*->comm\>'
  git grep 'strncpy.*->comm\>'
  git grep 'strcpy.*->comm\>'

PATCH #2~#4:   memcpy
PATCH #5~#6:   kstrdup
PATCH #7:      strcpy

Please note that strncpy() is not included in this series as it is being
tracked by another effort. [1]


This patch (of 7):

We want to eliminate the use of __get_task_comm() for the following
reasons:

- The task_lock() is unnecessary
  Quoted from Linus [0]:
  : Since user space can randomly change their names anyway, using locking
  : was always wrong for readers (for writers it probably does make sense
  : to have some lock - although practically speaking nobody cares there
  : either, but at least for a writer some kind of race could have
  : long-term mixed results

Link: https://lkml.kernel.org/r/20241007144911.27693-1-laoar.shao@gmail.com
Link: https://lkml.kernel.org/r/20241007144911.27693-2-laoar.shao@gmail.com
Link: https://lore.kernel.org/all/CAHk-=wivfrF0_zvf+oj6==Sh=-npJooP8chLPEfaFV0oNYTTBA@mail.gmail.com [0]
Link: https://lore.kernel.org/all/CAHk-=whWtUC-AjmGJveAETKOMeMFSTwKwu99v7+b6AyHMmaDFA@mail.gmail.com/
Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0]
Link: https://github.com/KSPP/linux/issues/90 [1]
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Matus Jokay <matus.jokay@stuba.sk>
Cc: Alejandro Colomar <alx@kernel.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 17:12:28 -08:00
..
array.c get rid of __get_task_comm() 2024-11-05 17:12:28 -08:00
base.c In the v6.12 scheduler development cycle we had 63 commits from 18 contributors: 2024-09-19 15:55:58 +02:00
bootconfig.c fs/proc: Skip bootloader comment if no embedded kernel parameters 2024-04-09 23:36:18 +09:00
cmdline.c proc: mark /proc/cmdline as permanent 2023-02-02 22:50:02 -08:00
consoles.c proc: Add nbcon support for /proc/consoles 2024-09-04 15:56:33 +02:00
cpuinfo.c x86/aperfmperf: Replace aperfmperf_get_khz() 2022-04-27 20:22:19 +02:00
devices.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
fd.c proc: Fix W=1 build kernel-doc warning 2024-10-18 13:02:47 +02:00
fd.h fs: port ->permission() to pass mnt_idmap 2023-01-19 09:24:28 +01:00
generic.c proc: fold kmalloc() + strcpy() into kmemdup() 2024-09-09 10:51:20 +02:00
inode.c proc: use __auto_type more 2024-09-17 01:11:20 -07:00
internal.h ALong with the usual shower of singleton patches, notable patch series in 2024-09-21 07:29:05 -07:00
interrupts.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
Kconfig crash: split vmcoreinfo exporting code out from crash_core.c 2024-02-23 17:48:22 -08:00
kcore.c fs/proc/kcore.c: allow translation of physical memory addresses 2024-10-09 12:47:19 -07:00
kmsg.c printk changes for 6.1 2022-10-10 11:24:19 -07:00
loadavg.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
Makefile kbuild: make -Woverride-init warnings more consistent 2024-03-31 11:32:26 +09:00
meminfo.c mm: zswap: optimize zswap pool size tracking 2024-04-25 20:55:47 -07:00
namespaces.c Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-01-29 11:20:24 -08:00
nommu.c fs: create helper file_user_path() for user displayed mapped file path 2023-10-19 11:03:15 +02:00
page.c x86: remove PG_uncached 2024-09-03 21:15:46 -07:00
proc_net.c fs: Add kernel-doc comments to proc_create_net_data_write() 2024-03-26 09:01:18 +01:00
proc_sysctl.c sysctl: avoid spurious permanent empty tables 2024-09-02 10:37:37 +02:00
proc_tty.c proc: delete unused <linux/uaccess.h> includes 2022-07-17 17:31:39 -07:00
root.c procfs: make freeing proc_fs_info rcu-delayed 2024-02-25 02:10:32 -05:00
self.c proc: convert to new timestamp accessors 2023-10-18 14:08:26 +02:00
softirqs.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
stat.c proc/stat: remove arch_idle_time() 2023-04-18 16:39:33 -07:00
task_mmu.c fs/proc: fix build with GCC 15 due to -Werror=unterminated-string-initialization 2024-10-17 00:28:07 -07:00
task_nommu.c vfs-6.7.misc 2023-10-30 09:14:19 -10:00
thread_self.c proc: convert to new timestamp accessors 2023-10-18 14:08:26 +02:00
uptime.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
util.c fs/proc/util.c: include fs/proc/internal.h for name_to_int() 2019-01-04 13:13:45 -08:00
version.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
vmcore.c fs/proc: fix softlockup in __read_vmcore 2024-05-11 15:51:44 -07:00