'buf[2]' is 2 bytes length, and sprintf() will append '\0' at the end
of string "?\n", so original implementation is memory overflow.
Need use strncpy() and strnlen() instead of sprintf().
Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
---
arch/s390/appldata/appldata_base.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/s390/appldata/appldata_base.c b/arch/s390/appldata/appldata_base.c
index bae0f40..87a2209 100644
--- a/arch/s390/appldata/appldata_base.c
+++ b/arch/s390/appldata/appldata_base.c
@@ -212,7 +212,9 @@ appldata_timer_handler(ctl_table *ctl, int write,
return 0;
}
if (!write) {
- len = sprintf(buf, appldata_timer_active ? "1\n" : "0\n");
+ strncpy(buf, appldata_timer_active ? "1\n" : "0\n",
+ ARRAY_SIZE(buf));
+ len = strnlen(buf, ARRAY_SIZE(buf));
if (len > *lenp)
len = *lenp;
if (copy_to_user(buffer, buf, len))
@@ -317,7 +319,8 @@ appldata_generic_handler(ctl_table *ctl, int write,
return 0;
}
if (!write) {
- len = sprintf(buf, ops->active ? "1\n" : "0\n");
+ strncpy(buf, ops->active ? "1\n" : "0\n", ARRAY_SIZE(buf));
+ len = strnlen(buf, ARRAY_SIZE(buf));
if (len > *lenp)
len = *lenp;
if (copy_to_user(buffer, buf, len)) {
--
1.7.7.6
--
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