Patch "ftrace: Fix memory leak in ftrace_graph_release()" has been added to the 4.11-stable tree

Patch "ftrace: Fix memory leak in ftrace_graph_release()" has been added to the 4.11-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ftrace: Fix memory leak in ftrace_graph_release()

to the 4.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ftrace-fix-memory-leak-in-ftrace_graph_release.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f9797c2f20c0160edd718aa467101f3301e57e59 Mon Sep 17 00:00:00 2001
From: Luis Henriques <lhenriques@suse.com>
Date: Thu, 25 May 2017 16:20:38 +0100
Subject: ftrace: Fix memory leak in ftrace_graph_release()

From: Luis Henriques <lhenriques@suse.com>

commit f9797c2f20c0160edd718aa467101f3301e57e59 upstream.

ftrace_hash is being kfree'ed in ftrace_graph_release(), however the
->buckets field is not.  This results in a memory leak that is easily
captured by kmemleak:

unreferenced object 0xffff880038afe000 (size 8192):
  comm "trace-cmd", pid 238, jiffies 4294916898 (age 9.736s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff815f561e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff8113964d>] __kmalloc+0x12d/0x1a0
    [<ffffffff810bf6d1>] alloc_ftrace_hash+0x51/0x80
    [<ffffffff810c0523>] __ftrace_graph_open.isra.39.constprop.46+0xa3/0x100
    [<ffffffff810c05e8>] ftrace_graph_open+0x68/0xa0
    [<ffffffff8114003d>] do_dentry_open.isra.1+0x1bd/0x2d0
    [<ffffffff81140df7>] vfs_open+0x47/0x60
    [<ffffffff81150f95>] path_openat+0x2a5/0x1020
    [<ffffffff81152d6a>] do_filp_open+0x8a/0xf0
    [<ffffffff811411df>] do_sys_open+0x12f/0x200
    [<ffffffff811412ce>] SyS_open+0x1e/0x20
    [<ffffffff815fa6e0>] entry_SYSCALL_64_fastpath+0x13/0x94
    [<ffffffffffffffff>] 0xffffffffffffffff

Link: http://lkml.kernel.org/r/20170525152038.7661-1-lhenriques@suse.com

Fixes: b9b0c831bed2 ("ftrace: Convert graph filter to use hash tables")
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/trace/ftrace.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4859,7 +4859,7 @@ ftrace_graph_release(struct inode *inode
 	}
 
  out:
-	kfree(fgd->new_hash);
+	free_ftrace_hash(fgd->new_hash);
 	kfree(fgd);
 
 	return ret;


Patches currently in stable-queue which might be from lhenriques@suse.com are

queue-4.11/ftrace-fix-memory-leak-in-ftrace_graph_release.patch