tty: nozomi: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Also rewrite the code in a standard if-form instead of ugly
conditional operators.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200311092905.24362-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Iwai 2020-03-11 10:29:05 +01:00 committed by Greg Kroah-Hartman
parent e39c0ffe8c
commit caa47cc639

View File

@ -839,40 +839,39 @@ static char *interrupt2str(u16 interrupt)
static char buf[TMP_BUF_MAX];
char *p = buf;
interrupt & MDM_DL1 ? p += snprintf(p, TMP_BUF_MAX, "MDM_DL1 ") : NULL;
interrupt & MDM_DL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"MDM_DL2 ") : NULL;
if (interrupt & MDM_DL1)
p += scnprintf(p, TMP_BUF_MAX, "MDM_DL1 ");
if (interrupt & MDM_DL2)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_DL2 ");
if (interrupt & MDM_UL1)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_UL1 ");
if (interrupt & MDM_UL2)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "MDM_UL2 ");
if (interrupt & DIAG_DL1)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_DL1 ");
if (interrupt & DIAG_DL2)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_DL2 ");
interrupt & MDM_UL1 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"MDM_UL1 ") : NULL;
interrupt & MDM_UL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"MDM_UL2 ") : NULL;
if (interrupt & DIAG_UL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "DIAG_UL ");
interrupt & DIAG_DL1 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"DIAG_DL1 ") : NULL;
interrupt & DIAG_DL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"DIAG_DL2 ") : NULL;
if (interrupt & APP1_DL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP1_DL ");
if (interrupt & APP2_DL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP2_DL ");
interrupt & DIAG_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"DIAG_UL ") : NULL;
if (interrupt & APP1_UL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP1_UL ");
if (interrupt & APP2_UL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "APP2_UL ");
interrupt & APP1_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"APP1_DL ") : NULL;
interrupt & APP2_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"APP2_DL ") : NULL;
if (interrupt & CTRL_DL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "CTRL_DL ");
if (interrupt & CTRL_UL)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "CTRL_UL ");
interrupt & APP1_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"APP1_UL ") : NULL;
interrupt & APP2_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"APP2_UL ") : NULL;
interrupt & CTRL_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"CTRL_DL ") : NULL;
interrupt & CTRL_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"CTRL_UL ") : NULL;
interrupt & RESET ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
"RESET ") : NULL;
if (interrupt & RESET)
p += scnprintf(p, TMP_BUF_MAX - (p - buf), "RESET ");
return buf;
}