[PATCH] usb: dwc3: Fix dentry leak in dwc3_gadget_free_endpoints

From: Cixi Geng
Date: Fri Oct 28 2022 - 04:49:33 EST


From: Bruce Chen <bruce.chen@xxxxxxxxxx>

When using debugfs_remove_recursive leaks a dentry with
a hotplug stress test, the phone runs out of memory.

Thus fix the issue by using the newly created debugfs_lookup_and_remove().

Signed-off-by: Bruce Chen <bruce.chen@xxxxxxxxxx>
Signed-off-by: Cixi Geng <cixi.geng1@xxxxxxxxxx>
---
drivers/usb/dwc3/core.h | 1 +
drivers/usb/dwc3/debugfs.c | 3 ++-
drivers/usb/dwc3/gadget.c | 4 +---
3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 8f9959ba9fd4..ba3ecaa7f06c 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1261,6 +1261,7 @@ struct dwc3 {
u8 num_eps;

struct dwc3_hwparams hwparams;
+ struct dentry *root;
struct debugfs_regset32 *regset;

u32 dbg_lsp_select;
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index f2b7675c7f62..b9af4a81f51d 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -911,6 +911,7 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
dwc->regset->base = dwc->regs - DWC3_GLOBALS_REGS_START;

root = debugfs_create_dir(dev_name(dwc->dev), usb_debug_root);
+ dwc->root = root;
debugfs_create_regset32("regdump", 0444, root, dwc->regset);
debugfs_create_file("lsp_dump", 0644, root, dwc, &dwc3_lsp_fops);

@@ -929,6 +930,6 @@ void dwc3_debugfs_init(struct dwc3 *dwc)

void dwc3_debugfs_exit(struct dwc3 *dwc)
{
- debugfs_remove(debugfs_lookup(dev_name(dwc->dev), usb_debug_root));
+ debugfs_remove(dwc->root);
kfree(dwc->regset);
}
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 079cd333632e..6d6c188fcbea 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3172,9 +3172,7 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
list_del(&dep->endpoint.ep_list);
}

- debugfs_remove_recursive(debugfs_lookup(dep->name,
- debugfs_lookup(dev_name(dep->dwc->dev),
- usb_debug_root)));
+ debugfs_lookup_and_remove(dep->name, dwc->root);
kfree(dep);
}
}
--
2.34.1