From: "Steven Rostedt (Google)" rostedt@goodmis.org

mainline inclusion from mainline-v6.6-rc2 commit 7d660c9b2bc95107f90a9f4c4759be85309a6550 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IATD5H

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

--------------------------------

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 Conflicts: kernel/trace/trace.c [adjust context conflicts] Signed-off-by: Chen Zhongjin chenzhongjin@huawei.com --- kernel/trace/trace.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3c776919305a..a470950b8ed6 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1718,7 +1718,7 @@ 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); }

@@ -1752,7 +1752,7 @@ 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)

#else #define trace_create_maxlat_file(tr, d_tracer) do { } while (0) @@ -6227,14 +6227,18 @@ 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 @@ -7264,10 +7268,11 @@ static const struct file_operations tracing_thresh_fops = {

#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) 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