This is a note to let you know that I've just added the patch titled fs: dlm: fix configfs memory leak to the 4.9-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: fs-dlm-fix-configfs-memory-leak.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5267df6571891cdc38678f4b34d827877d4aa978 Author: Alexander Aring <aahringo@xxxxxxxxxx> Date: Thu Aug 27 15:02:51 2020 -0400 fs: dlm: fix configfs memory leak [ Upstream commit 3d2825c8c6105b0f36f3ff72760799fa2e71420e ] This patch fixes the following memory detected by kmemleak and umount gfs2 filesystem which removed the last lockspace: unreferenced object 0xffff9264f482f600 (size 192): comm "dlm_controld", pid 325, jiffies 4294690276 (age 48.136s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 6e 6f 64 65 73 00 00 00 ........nodes... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000060481d7>] make_space+0x41/0x130 [<000000008d905d46>] configfs_mkdir+0x1a2/0x5f0 [<00000000729502cf>] vfs_mkdir+0x155/0x210 [<000000000369bcf1>] do_mkdirat+0x6d/0x110 [<00000000cc478a33>] do_syscall_64+0x33/0x40 [<00000000ce9ccf01>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 The patch just remembers the "nodes" entry pointer in space as I think it's created as subdirectory when parent "spaces" is created. In function drop_space() we will lost the pointer reference to nds because configfs_remove_default_groups(). However as this subdirectory is always available when "spaces" exists it will just be freed when "spaces" will be freed. Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx> Signed-off-by: David Teigland <teigland@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/dlm/config.c b/fs/dlm/config.c index df955d2209ce9..6def89d2209d3 100644 --- a/fs/dlm/config.c +++ b/fs/dlm/config.c @@ -218,6 +218,7 @@ struct dlm_space { struct list_head members; struct mutex members_lock; int members_count; + struct dlm_nodes *nds; }; struct dlm_comms { @@ -426,6 +427,7 @@ static struct config_group *make_space(struct config_group *g, const char *name) INIT_LIST_HEAD(&sp->members); mutex_init(&sp->members_lock); sp->members_count = 0; + sp->nds = nds; return &sp->group; fail: @@ -447,6 +449,7 @@ static void drop_space(struct config_group *g, struct config_item *i) static void release_space(struct config_item *i) { struct dlm_space *sp = config_item_to_space(i); + kfree(sp->nds); kfree(sp); }