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authorSteven Rostedt (Google) <rostedt@goodmis.org>2023-09-06 22:47:13 -0400
committerSteven Rostedt (Google) <rostedt@goodmis.org>2023-09-07 16:38:53 -0400
commit7d660c9b2bc95107f90a9f4c4759be85309a6550 (patch)
tree7464736c2035613262ca7055990daa8384baf5d0 /kernel
parentf5ca233e2e66dc1c249bf07eefa37e34a6c9346a (diff)
tracing: Have tracing_max_latency inc the trace array ref count
The tracing_max_latency file points to the trace_array max_latency field. For an instance, if the file is opened and the instance is deleted, reading or writing to the file will cause a use after free. Up the ref count of the trace_array when tracing_max_latency is opened. Link: https://lkml.kernel.org/r/20230907024803.666889383@goodmis.org Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Zheng Yejian <zhengyejian1@huawei.com> Fixes: 8530dec63e7b4 ("tracing: Add tracing_check_open_get_tr()") Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0827037ee3b8..c8b8b4c6feaf 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1772,7 +1772,7 @@ static void trace_create_maxlat_file(struct trace_array *tr,
init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
tr->d_max_latency = trace_create_file("tracing_max_latency",
TRACE_MODE_WRITE,
- d_tracer, &tr->max_latency,
+ d_tracer, tr,
&tracing_max_lat_fops);
}
@@ -1805,7 +1805,7 @@ void latency_fsnotify(struct trace_array *tr)
#define trace_create_maxlat_file(tr, d_tracer) \
trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \
- d_tracer, &tr->max_latency, &tracing_max_lat_fops)
+ d_tracer, tr, &tracing_max_lat_fops)
#endif
@@ -6717,14 +6717,18 @@ static ssize_t
tracing_max_lat_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
- return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos);
+ struct trace_array *tr = filp->private_data;
+
+ return tracing_nsecs_read(&tr->max_latency, ubuf, cnt, ppos);
}
static ssize_t
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
- return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos);
+ struct trace_array *tr = filp->private_data;
+
+ return tracing_nsecs_write(&tr->max_latency, ubuf, cnt, ppos);
}
#endif
@@ -7778,10 +7782,11 @@ static const struct file_operations tracing_thresh_fops = {
#ifdef CONFIG_TRACER_MAX_TRACE
static const struct file_operations tracing_max_lat_fops = {
- .open = tracing_open_generic,
+ .open = tracing_open_generic_tr,
.read = tracing_max_lat_read,
.write = tracing_max_lat_write,
.llseek = generic_file_llseek,
+ .release = tracing_release_generic_tr,
};
#endif