ARM: 9300/1: 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

[ardb: submitting to the patch tracker on behalf of Azeem]

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/kernel/atags_parse.c b/arch/arm/kernel/atags_parse.c
index 373b61f9a4f01c17fba7a5d4398034129a43f3d1..33f6eb5213a5a8c9aabbd2a5c3f20188e2144e32 100644 (file)
--- a/arch/arm/kernel/atags_parse.c
+++ b/arch/arm/kernel/atags_parse.c
@@ -127,7 +127,7 @@ static int __init parse_tag_cmdline(const struct tag *tag)
 #elif defined(CONFIG_CMDLINE_FORCE)
        pr_warn("Ignoring tag cmdline (using the default kernel command line)\n");
 #else
-       strlcpy(default_command_line, tag->u.cmdline.cmdline,
+       strscpy(default_command_line, tag->u.cmdline.cmdline,
                COMMAND_LINE_SIZE);
 #endif
        return 0;
@@ -224,7 +224,7 @@ setup_machine_tags(void *atags_vaddr, unsigned int machine_nr)
        }
 
        /* parse_early_param needs a boot_command_line */
-       strlcpy(boot_command_line, from, COMMAND_LINE_SIZE);
+       strscpy(boot_command_line, from, COMMAND_LINE_SIZE);
 
        return mdesc;
 }

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 0a26585f5027853a1c5dd42d68b5815421bb9e2d..a2f54ea089887e32efa51b1361409effdb43de90 100644 (file)
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1142,7 +1142,7 @@ void __init setup_arch(char **cmdline_p)
        setup_initial_init_mm(_text, _etext, _edata, _end);
 
        /* populate cmd_line too for later use, preserving boot_command_line */
-       strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
+       strscpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
        *cmdline_p = cmd_line;
 
        early_fixmap_init();

diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 3408269d19c7dc1181cf1512531a2788a1b3c41b..f297d66a8a7624daca23ad2ff052c504fb859b34 100644 (file)
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -135,7 +135,7 @@ static Elf32_Sym * __init find_symbol(struct elfinfo *lib, const char *symname)
 
                if (lib->dynsym[i].st_name == 0)
                        continue;
-               strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
+               strscpy(name, lib->dynstr + lib->dynsym[i].st_name,
                        MAX_SYMNAME);
                c = strchr(name, '@');
                if (c)