From d5a821896360cc8b93a15bd888fabc858c038dc0 Mon Sep 17 00:00:00 2001 From: Zheng Yejian Date: Thu, 13 Jul 2023 22:14:35 +0800 Subject: [PATCH] tracing: Fix memory leak of iter->temp when reading trace_pipe kmemleak reports: unreferenced object 0xffff88814d14e200 (size 256): comm "cat", pid 336, jiffies 4294871818 (age 779.490s) hex dump (first 32 bytes): 04 00 01 03 00 00 00 00 08 00 00 00 00 00 00 00 ................ 0c d8 c8 9b ff ff ff ff 04 5a ca 9b ff ff ff ff .........Z...... backtrace: [] __kmalloc+0x4f/0x140 [] trace_find_next_entry+0xbb/0x1d0 [] trace_print_lat_context+0xaf/0x4e0 [] print_trace_line+0x3e0/0x950 [] tracing_read_pipe+0x2d9/0x5a0 [] vfs_read+0x143/0x520 [] ksys_read+0xbd/0x160 [] do_syscall_64+0x3f/0x90 [] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 when reading file 'trace_pipe', 'iter->temp' is allocated or relocated in trace_find_next_entry() but not freed before 'trace_pipe' is closed. To fix it, free 'iter->temp' in tracing_release_pipe(). Link: https://lore.kernel.org/linux-trace-kernel/20230713141435.1133021-1-zhengyejian1@huawei.com Cc: stable@vger.kernel.org Fixes: ff895103a84ab ("tracing: Save off entry when peeking at next entry") Signed-off-by: Zheng Yejian Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20122ee..be847d4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6781,6 +6781,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) free_cpumask_var(iter->started); kfree(iter->fmt); + kfree(iter->temp); mutex_destroy(&iter->mutex); kfree(iter); -- 2.7.4