This is a note to let you know that I've just added the patch titled
ftrace: Fix memory leak caused by not freeing entry in unregister_ftrace_direct()
to the 5.6-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-caused-by-not-freeing-entry-i.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ae81b7340178886f6cec3d6da748770ed3119dba
Author: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Date: Wed Apr 22 21:38:45 2020 -0400
ftrace: Fix memory leak caused by not freeing entry in unregister_ftrace_direct()
[ Upstream commit 353da87921a5ec654e7e9024e083f099f1b33c97 ]
kmemleak reported the following:
unreferenced object 0xffff90d47127a920 (size 32):
comm "modprobe", pid 1766, jiffies 4294792031 (age 162.568s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 22 01 00 00 00 00 ad de ........".......
00 78 12 a7 ff ff ff ff 00 00 b6 c0 ff ff ff ff .x..............
backtrace:
[<00000000bb79e72e>] register_ftrace_direct+0xcb/0x3a0
[<00000000295e4f79>] do_one_initcall+0x72/0x340
[<00000000873ead18>] do_init_module+0x5a/0x220
[<00000000974d9de5>] load_module+0x2235/0x2550
[<0000000059c3d6ce>] __do_sys_finit_module+0xc0/0x120
[<000000005a8611b4>] do_syscall_64+0x60/0x230
[<00000000a0cdc49e>] entry_SYSCALL_64_after_hwframe+0x49/0xb3
The entry used to save the direct descriptor needs to be freed
when unregistering.
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fd81c7de77a70..63089c70adbb6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5155,6 +5155,7 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
list_del_rcu(&direct->next);
synchronize_rcu_tasks();
kfree(direct);
+ kfree(entry);
ftrace_direct_func_count--;
}
}
