4.14-stable review patch. If anyone has any objections, please let me know.
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From: Tony Luck tony.luck@intel.com
commit 985c78d3ff8e9c74450fa2bb08eb55e680d999ca upstream.
Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE] in flags_read() is two characters long. But the sprintf() adds a trailing newline and will add a terminating NUL byte. So MAX_FLAG_OPT_SIZE needs to be 4.
sprintf() calls vsnprintf() and *that* does return:
" * The return value is the number of characters which would * be generated for the given input, excluding the trailing * '\0', as per ISO C99."
Note the "excluding".
Reported-by: Dmitry Vyukov dvyukov@google.com Signed-off-by: Tony Luck tony.luck@intel.com Signed-off-by: Borislav Petkov bp@suse.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Cc: linux-edac linux-edac@vger.kernel.org Link: http://lkml.kernel.org/r/20180427163707.ktaiysvbk3yhk4wm@agluck-desk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/mcheck/mce-inject.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -48,7 +48,7 @@ static struct dentry *dfs_inj;
static u8 n_banks;
-#define MAX_FLAG_OPT_SIZE 3 +#define MAX_FLAG_OPT_SIZE 4 #define NBCFG 0x44
enum injection_type {