um: Remove strlcpy usage

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>
[rw: Massaged subject]
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Azeem Shaikh 2023-07-03 16:06:41 +00:00 committed by Richard Weinberger
parent 2ccdd1b13c
commit f5ff432d96
2 changed files with 3 additions and 4 deletions

View File

@ -50,7 +50,6 @@ static inline int printk(const char *fmt, ...)
#endif
extern int in_aton(char *str);
extern size_t strlcpy(char *, const char *, size_t);
extern size_t strlcat(char *, const char *, size_t);
extern size_t strscpy(char *, const char *, size_t);

View File

@ -40,7 +40,7 @@ static int __init make_uml_dir(void)
__func__);
goto err;
}
strlcpy(dir, home, sizeof(dir));
strscpy(dir, home, sizeof(dir));
uml_dir++;
}
strlcat(dir, uml_dir, sizeof(dir));
@ -243,7 +243,7 @@ int __init set_umid(char *name)
if (strlen(name) > UMID_LEN - 1)
return -E2BIG;
strlcpy(umid, name, sizeof(umid));
strscpy(umid, name, sizeof(umid));
return 0;
}
@ -262,7 +262,7 @@ static int __init make_umid(void)
make_uml_dir();
if (*umid == '\0') {
strlcpy(tmp, uml_dir, sizeof(tmp));
strscpy(tmp, uml_dir, sizeof(tmp));
strlcat(tmp, "XXXXXX", sizeof(tmp));
fd = mkstemp(tmp);
if (fd < 0) {