From c642256b91770e201519d037a91f255a617a4602 Mon Sep 17 00:00:00 2001
From: Azeem Shaikh <azeemshaikh38@gmail.com>
Date: Wed, 10 May 2023 22:11:19 +0000
Subject: [PATCH] vfs: Replace all non-returning strlcpy with strscpy
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>
Reviewed-by: Kees Cook <keescook@chromium.org>
Message-Id: <20230510221119.3508930-1-azeemshaikh38@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
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 13deb45f1ec65..950b6919fb872 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 34afe411cf2bc..8d8d68799b34f 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);
--
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