[for-next][PATCH 13/14] tracing: Fix uninitialized buffer var on early exit to trace_vbprintk()

From: Steven Rostedt
Date: Fri Jan 24 2020 - 10:17:32 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

If we exit due to a bad input to trace_printk() (highly unlikely), then the
buffer variable will not be initialized when we unnest the ring buffer.

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2e1db19dce97..d1410b4462ac 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3230,7 +3230,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);

if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
- goto out;
+ goto out_put;

local_save_flags(flags);
size = sizeof(*entry) + sizeof(u32) * len;
@@ -3252,6 +3252,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)

out:
ring_buffer_nest_end(buffer);
+out_put:
put_trace_buf();

out_nobuffer:
--
2.24.1