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

Revert "kernfs: fix memleak in kernel_ops_readdir()"

to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 8097c43bcbec56fbd0788d99e1e236c0e0d4013f Mon Sep 17 00:00:00 2001

From: Greg Kroah-Hartman gregkh@linuxfoundation.org Date: Thu, 8 Aug 2019 08:39:35 +0200 Subject: Revert "kernfs: fix memleak in kernel_ops_readdir()"

This reverts commit cc798c83898ea0a77fcaa1a92afda35c3c3ded74.

Tony writes: Somehow this causes a regression in Linux next for me where I'm seeing lots of sysfs entries now missing under /sys/bus/platform/devices.

For example, I now only see one .serial entry show up in sysfs. Things work again if I revert commit cc798c83898e ("kernfs: fix memleak inkernel_ops_readdir()"). Any ideas why that would be?

Tejun says: Ugh, you're right. It can get double-put cuz ctx->pos is put by release too.

So reverting it for now.

Reported-by: Tony Lindgren tony@atomide.com Cc: Andrea Arcangeli aarcange@redhat.com Cc: Tejun Heo tj@kernel.org Fixes: cc798c83898e ("kernfs: fix memleak in kernel_ops_readdir()") Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/kernfs/dir.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 1e98efc2bf6d..a387534c9577 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -1684,14 +1684,11 @@ static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) kernfs_get(pos);

mutex_unlock(&kernfs_mutex); - if (unlikely(!dir_emit(ctx, name, len, ino, type))) { - kernfs_put(pos); - goto out; - } + if (!dir_emit(ctx, name, len, ino, type)) + return 0; mutex_lock(&kernfs_mutex); } mutex_unlock(&kernfs_mutex); -out: file->private_data = NULL; ctx->pos = INT_MAX; return 0;