diff options
| author | Justin Stitt <justinstitt@google.com> | 2023-08-24 18:52:18 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-08-24 21:22:06 +0200 |
| commit | 1e6f01f7285559a5302e85677b8e59a5de9b0ea5 (patch) | |
| tree | ebf3313eff6c8baea7dd10ac222b9af5afdf87d8 | |
| parent | 8874a414f8f706daf1de467cbf2550988ebec09d (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>
| -rw-r--r-- | arch/x86/platform/uv/uv_nmi.c | 12 |
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 */ |