diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-10-11 17:22:50 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-10-12 20:48:06 -0400 |
| commit | 17911ff38aa58d3c95c07589dbf5d3564c4cf3c5 (patch) | |
| tree | 0437649533f3c50b4207fd9368bf47ae06bcfe95 /kernel/trace/trace_events.c | |
| parent | 8530dec63e7b486e3761cc3d74a22de301845ff5 (diff) | |
tracing: Add locked_down checks to the open calls of files created for tracefs
Added various checks on open tracefs calls to see if tracefs is in lockdown
mode, and if so, to return -EPERM.
Note, the event format files (which are basically standard on all machines)
as well as the enabled_functions file (which shows what is currently being
traced) are not lockde down. Perhaps they should be, but it seems counter
intuitive to lockdown information to help you know if the system has been
modified.
Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 71ab0a3660f4..fba87d10f0c1 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -12,6 +12,7 @@ #define pr_fmt(fmt) fmt #include <linux/workqueue.h> +#include <linux/security.h> #include <linux/spinlock.h> #include <linux/kthread.h> #include <linux/tracefs.h> @@ -1294,6 +1295,8 @@ static int trace_format_open(struct inode *inode, struct file *file) struct seq_file *m; int ret; + /* Do we want to hide event format files on tracefs lockdown? */ + ret = seq_open(file, &trace_format_seq_ops); if (ret < 0) return ret; @@ -1760,6 +1763,10 @@ ftrace_event_open(struct inode *inode, struct file *file, struct seq_file *m; int ret; + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + ret = seq_open(file, seq_ops); if (ret < 0) return ret; @@ -1784,6 +1791,7 @@ ftrace_event_avail_open(struct inode *inode, struct file *file) { const struct seq_operations *seq_ops = &show_event_seq_ops; + /* Checks for tracefs lockdown */ return ftrace_event_open(inode, file, seq_ops); } |