@@ -230,7 +230,10 @@ void proc_comm_connector(struct task_struct *task)
ev->what = PROC_EVENT_COMM;
ev->event_data.comm.process_pid = task->pid;
ev->event_data.comm.process_tgid = task->tgid;
- get_task_comm(ev->event_data.comm.comm, task);
+
+ /* This may get truncated. */
+ __get_task_comm(ev->event_data.comm.comm,
+ sizeof(ev->event_data.comm.comm), task);
memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
msg->ack = 0; /* not used */
@@ -21,6 +21,11 @@
#include <linux/types.h>
+/* We can't include <linux/sched.h> directly in this UAPI header. */
+#ifndef TASK_COMM_LEN_16
+#define TASK_COMM_LEN_16 16
+#endif
+
/*
* Userspace sends this enum to register with the kernel that it is listening
* for events on the connector.
@@ -110,7 +115,7 @@ struct proc_event {
struct comm_proc_event {
__kernel_pid_t process_pid;
__kernel_pid_t process_tgid;
- char comm[16];
+ char comm[TASK_COMM_LEN_16];
} comm;
struct coredump_proc_event {
connector comm was introduced in commit f786ecba4158 ("connector: add comm change event report to proc connector"). struct comm_proc_event was defined in include/linux/cn_proc.h first and then been moved into file include/uapi/linux/cn_proc.h in commit 607ca46e97a1 ("UAPI: (Scripted) Disintegrate include/linux"). As this is the UAPI code, we can't change it without potentially breaking things (i.e. userspace binaries have this size built in, so we can't just change the size). To prepare for the followup change - extending task comm, we have to use __get_task_comm() to avoid the BUILD_BUG_ON() in proc_comm_connector(). __get_task_comm() always get a nul terminated string, so we don't worry about whether it is truncated or not. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Vladimir Zapolskiy <vzapolskiy@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: David Howells <dhowells@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Petr Mladek <pmladek@suse.com> --- drivers/connector/cn_proc.c | 5 ++++- include/uapi/linux/cn_proc.h | 7 ++++++- 2 files changed, 10 insertions(+), 2 deletions(-)