6.12-stable review patch. If anyone has any objections, please let me know.
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From: Al Viro viro@zeniv.linux.org.uk
[ Upstream commit 60a6002432448bb3f291d80768ae98d62efc9c77 ]
strcpy() should not be used with destination potentially overlapping the source; what's more, strscpy() in there is pointless - we already know the amount we want to copy; might as well use memcpy().
Fixes: c278e81b8a02 "hostfs: Remove open coded strcpy()" Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/hostfs/hostfs_kern.c | 27 ++++++--------------------- 1 file changed, 6 insertions(+), 21 deletions(-)
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 084f6ed2dd7a6..94f3cc42c7403 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -94,32 +94,17 @@ __uml_setup("hostfs=", hostfs_args, static char *__dentry_name(struct dentry *dentry, char *name) { char *p = dentry_path_raw(dentry, name, PATH_MAX); - char *root; - size_t len; - struct hostfs_fs_info *fsi; - - fsi = dentry->d_sb->s_fs_info; - root = fsi->host_root_path; - len = strlen(root); - if (IS_ERR(p)) { - __putname(name); - return NULL; - } - - /* - * This function relies on the fact that dentry_path_raw() will place - * the path name at the end of the provided buffer. - */ - BUG_ON(p + strlen(p) + 1 != name + PATH_MAX); + struct hostfs_fs_info *fsi = dentry->d_sb->s_fs_info; + char *root = fsi->host_root_path; + size_t len = strlen(root);
- strscpy(name, root, PATH_MAX); - if (len > p - name) { + if (IS_ERR(p) || len > p - name) { __putname(name); return NULL; }
- if (p > name + len) - strcpy(name + len, p); + memcpy(name, root, len); + memmove(name + len, p, name + PATH_MAX - p);
return name; }