The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x d5a821896360cc8b93a15bd888fabc858c038dc0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023072128-pavilion-employer-0a22@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

d5a821896360 ("tracing: Fix memory leak of iter->temp when reading trace_pipe") 649e72070cbb ("tracing: Fix memory leak in tracing_read_pipe()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d5a821896360cc8b93a15bd888fabc858c038dc0 Mon Sep 17 00:00:00 2001 From: Zheng Yejian zhengyejian1@huawei.com 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: [<ffffffff9bdff18f>] __kmalloc+0x4f/0x140 [<ffffffff9bc9238b>] trace_find_next_entry+0xbb/0x1d0 [<ffffffff9bc9caef>] trace_print_lat_context+0xaf/0x4e0 [<ffffffff9bc94490>] print_trace_line+0x3e0/0x950 [<ffffffff9bc95499>] tracing_read_pipe+0x2d9/0x5a0 [<ffffffff9bf03a43>] vfs_read+0x143/0x520 [<ffffffff9bf04c2d>] ksys_read+0xbd/0x160 [<ffffffff9d0f0edf>] do_syscall_64+0x3f/0x90 [<ffffffff9d2000aa>] 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-zhengyej...

Cc: stable@vger.kernel.org Fixes: ff895103a84ab ("tracing: Save off entry when peeking at next entry") Signed-off-by: Zheng Yejian zhengyejian1@huawei.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20122eeccf97..be847d45d81c 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);