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authorJustin Stitt <justinstitt@google.com>2023-08-24 18:52:18 +0000
committerIngo Molnar <mingo@kernel.org>2023-08-24 21:22:06 +0200
commit1e6f01f7285559a5302e85677b8e59a5de9b0ea5 (patch)
treeebf3313eff6c8baea7dd10ac222b9af5afdf87d8 /arch/x86/platform
parent8874a414f8f706daf1de467cbf2550988ebec09d (diff)
x86/platform/uv: Refactor code using deprecated strcpy()/strncpy() interfaces to use strscpy()
Both `strncpy` and `strcpy` are deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy` or `strcpy`! In this case, we can drop both the forced NUL-termination and the `... -1` from: | strncpy(arg, val, ACTION_LEN - 1); as `strscpy` implicitly has this behavior. Also include slight refactor to code removing possible new-line chars as per Yang Yang's work at [3]. This reduces code size and complexity by using more robust and better understood interfaces. Co-developed-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Justin Stitt <justinstitt@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Dimitri Sivanich <sivanich@hpe.com> Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://lore.kernel.org/all/202212091545310085328@zte.com.cn/ [3] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/r/20230824-strncpy-arch-x86-platform-uv-uv_nmi-v2-1-e16d9a3ec570@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/platform')
-rw-r--r--arch/x86/platform/uv/uv_nmi.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
index a60af0230e27..a6ab43f69b7d 100644
--- a/arch/x86/platform/uv/uv_nmi.c
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -202,21 +202,17 @@ static int param_set_action(const char *val, const struct kernel_param *kp)
{
int i;
int n = ARRAY_SIZE(valid_acts);
- char arg[ACTION_LEN], *p;
+ char arg[ACTION_LEN];
/* (remove possible '\n') */
- strncpy(arg, val, ACTION_LEN - 1);
- arg[ACTION_LEN - 1] = '\0';
- p = strchr(arg, '\n');
- if (p)
- *p = '\0';
+ strscpy(arg, val, strnchrnul(val, sizeof(arg)-1, '\n') - val + 1);
for (i = 0; i < n; i++)
if (!strcmp(arg, valid_acts[i].action))
break;
if (i < n) {
- strcpy(uv_nmi_action, arg);
+ strscpy(uv_nmi_action, arg, sizeof(uv_nmi_action));
pr_info("UV: New NMI action:%s\n", uv_nmi_action);
return 0;
}
@@ -959,7 +955,7 @@ static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
/* Unexpected return, revert action to "dump" */
if (master)
- strncpy(uv_nmi_action, "dump", strlen(uv_nmi_action));
+ strscpy(uv_nmi_action, "dump", sizeof(uv_nmi_action));
}
/* Pause as all CPU's enter the NMI handler */