From: Azeem Shaikh <azeemshaikh38@xxxxxxxxx> [ Upstream commit c642256b91770e201519d037a91f255a617a4602 ] 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@xxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Message-Id: <20230510221119.3508930-1-azeemshaikh38@xxxxxxxxx> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 04bc62ab7dfea..09668ddfbbd55 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); -- 2.39.2
