From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] vfs: Replace all non-returning strlcpy with strscpy
Date: Wed, 10 May 2023 22:11:19 +0000 [thread overview]
Message-ID: <20230510221119.3508930-1-azeemshaikh38@gmail.com> (raw)
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
fs/char_dev.c | 2 +-
fs/super.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 13deb45f1ec6..950b6919fb87 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -150,7 +150,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
cd->major = major;
cd->baseminor = baseminor;
cd->minorct = minorct;
- strlcpy(cd->name, name, sizeof(cd->name));
+ strscpy(cd->name, name, sizeof(cd->name));
if (!prev) {
cd->next = curr;
diff --git a/fs/super.c b/fs/super.c
index 34afe411cf2b..8d8d68799b34 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -595,7 +595,7 @@ struct super_block *sget_fc(struct fs_context *fc,
fc->s_fs_info = NULL;
s->s_type = fc->fs_type;
s->s_iflags |= fc->s_iflags;
- strlcpy(s->s_id, s->s_type->name, sizeof(s->s_id));
+ strscpy(s->s_id, s->s_type->name, sizeof(s->s_id));
list_add_tail(&s->s_list, &super_blocks);
hlist_add_head(&s->s_instances, &s->s_type->fs_supers);
spin_unlock(&sb_lock);
@@ -674,7 +674,7 @@ struct super_block *sget(struct file_system_type *type,
return ERR_PTR(err);
}
s->s_type = type;
- strlcpy(s->s_id, type->name, sizeof(s->s_id));
+ strscpy(s->s_id, type->name, sizeof(s->s_id));
list_add_tail(&s->s_list, &super_blocks);
hlist_add_head(&s->s_instances, &type->fs_supers);
spin_unlock(&sb_lock);
next reply other threads:[~2023-05-10 22:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-10 22:11 Azeem Shaikh [this message]
2023-05-11 16:26 ` [PATCH] vfs: Replace all non-returning strlcpy with strscpy Kees Cook
2023-05-15 7:50 ` Christian Brauner
2023-05-16 20:37 ` Kees Cook
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