The patch titled
Subject: pid-namespace: limit value of ns_last_pid to (0, max_pid)
has been added to the -mm tree. Its filename is
pid-namespace-limit-value-of-ns_last_pid-to-0-max_pid.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Andrew Vagin <avagin@xxxxxxxxxx>
Subject: pid-namespace: limit value of ns_last_pid to (0, max_pid)
The kernel doesn't check the pid for negative values, so if you try to
write -2 to /proc/sys/kernel/ns_last_pid, you will get a kernel panic.
The crash happens because the next pid is -1, and alloc_pidmap() will try
to access to a nonexistent pidmap.
map = &pid_ns->pidmap[pid/BITS_PER_PAGE];
Signed-off-by: Andrew Vagin <avagin@xxxxxxxxxx>
Acked-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/pid_namespace.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff -puN kernel/pid_namespace.c~pid-namespace-limit-value-of-ns_last_pid-to-0-max_pid kernel/pid_namespace.c
--- a/kernel/pid_namespace.c~pid-namespace-limit-value-of-ns_last_pid-to-0-max_pid
+++ a/kernel/pid_namespace.c
@@ -232,15 +232,19 @@ static int pid_ns_ctl_handler(struct ctl
*/
tmp.data = ¤t->nsproxy->pid_ns->last_pid;
- return proc_dointvec(&tmp, write, buffer, lenp, ppos);
+ return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
}
+extern int pid_max;
+static int zero = 0;
static struct ctl_table pid_ns_ctl_table[] = {
{
.procname = "ns_last_pid",
.maxlen = sizeof(int),
.mode = 0666, /* permissions are checked in the handler */
.proc_handler = pid_ns_ctl_handler,
+ .extra1 = &zero,
+ .extra2 = &pid_max,
},
{ }
};
_
Patches currently in -mm which might be from avagin@xxxxxxxxxx are
pid-namespace-limit-value-of-ns_last_pid-to-0-max_pid.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
