Function panic() in kernel/panic.c will use panic_timeout
multiplying 1000 as a loop boundery. So this multiplication
can overflow when panic_timeout is greater than (INT_MAX/1000).
And this results in a zero-delay panic, instead of a huge
timeout as the user intends.
Fix this by adding bound check to make it no bigger than
(INT_MAX/1000).
Signed-off-by: Changming Liu <charley.ashbringer@xxxxxxxxx>
---
kernel/sysctl.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index db1ce7a..e60cf04 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -137,6 +137,9 @@ static int minolduid;
static int ngroups_max = NGROUPS_MAX;
static const int cap_last_cap = CAP_LAST_CAP;
+/* this is needed for setting boundery for panic_timeout to prevent it from overflow*/
+static int panic_time_max = INT_MAX / 1000;
+
/*
* This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs
* and hung_task_check_interval_secs
@@ -1857,7 +1860,8 @@ static struct ctl_table kern_table[] = {
.data = &panic_timeout,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra2 = &panic_time_max,
},
#ifdef CONFIG_COREDUMP
{
--
2.7.4
