[PATCH AUTOSEL 6.6 32/62] wireless: purelifi: plfxlc: fix memory leak in plfxlc_usb_wreq_asyn()

[Sasha Levin <sashal@kernel.org>]

From: Salah Triki <salah.triki@gmail.com>

[ Upstream commit 63a9a727d373fa5b8ce509eef50dbc45e0f745b9 ]

Add usb_free_urb() in the error path to prevent memory leak.

Signed-off-by: Salah Triki <salah.triki@gmail.com>
Link: https://patch.msgid.link/aA3_maPlEJzO7wrL@pc
[fix subject]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** This commit should be backported to stable kernel trees. Here's
my extensive analysis: ## Code Analysis The commit fixes a clear memory
leak in the `plfxlc_usb_wreq_async()` function in the pureLiFi wireless
driver. Specifically: **The Bug:** - The function calls
`usb_alloc_urb(0, GFP_ATOMIC)` to allocate a USB URB (USB Request Block)
- If `usb_submit_urb()` fails, the function returns the error code but
never frees the allocated URB - This creates a memory leak every time
USB submission fails **The Fix:** The fix adds a simple but crucial
cleanup path: ```c r = usb_submit_urb(urb, GFP_ATOMIC); -if (r) +if (r)
{ + usb_free_urb(urb); dev_err(&udev->dev, "Async write submit failed
(%d)\n", r); +} ``` ## Timeline and Impact From examining the git
history: 1. **Bug Introduction:** The bug was introduced in commit
`68d57a07bfe5` when the driver was first added 2. **Bug Duration:** This
memory leak has existed since the driver's introduction 3. **Impact:**
Every failed USB submission would leak memory, potentially causing
system instability over time ## Comparison with Similar Commits This
commit matches the pattern of all 5 similar commits marked as "Backport
Status: YES": 1. **Similar Commit #2** - Also fixes missing allocation
failure check in the same function (`plfxlc_usb_wreq_async`) 2.
**Similar Commit #1** - Fixes memory leak in the same driver
(`__lf_x_usb_enable_rx`) 3. **Similar Commits #3-5** - All fix memory
leaks in wireless drivers with small, contained changes ## Backport
Criteria Met ✅ **Fixes important bug:** Memory leaks can cause system
instability ✅ **Small and contained:** Only adds 2 lines of code in
error path ✅ **No architectural changes:** Simple cleanup fix ✅
**Minimal regression risk:** Standard USB cleanup pattern ✅ **Clear
scope:** Limited to specific function in wireless driver ✅ **Follows
stable rules:** Important bugfix with minimal impact ## Additional
Considerations - The fix follows standard kernel patterns for USB URB
cleanup - The same driver has had multiple similar memory leak fixes
(commit `895b3b06efc2`) - The change is identical in nature to Similar
Commit #2, which was also in this exact function and marked YES for
backporting - No side effects beyond fixing the memory leak - The
function is called from transmit path, so failures could be relatively
common under stress This is a textbook example of a stable tree
candidate: a clear, important bug fix with minimal code changes and no
risk of regression.

 drivers/net/wireless/purelifi/plfxlc/usb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/purelifi/plfxlc/usb.c b/drivers/net/wireless/purelifi/plfxlc/usb.c
index 311676c1ece0a..8151bc5e00ccc 100644
--- a/drivers/net/wireless/purelifi/plfxlc/usb.c
+++ b/drivers/net/wireless/purelifi/plfxlc/usb.c
@@ -503,8 +503,10 @@ int plfxlc_usb_wreq_async(struct plfxlc_usb *usb, const u8 *buffer,
 			  (void *)buffer, buffer_len, complete_fn, context);
 
 	r = usb_submit_urb(urb, GFP_ATOMIC);
-	if (r)
+	if (r) {
+		usb_free_urb(urb);
 		dev_err(&udev->dev, "Async write submit failed (%d)\n", r);
+	}
 
 	return r;
 }
-- 
2.39.5