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From: Josh Law <hlcj1234567@gmail.com>
To: Matthew Wilcox <willy@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Josh Law <objecting@objecting.org>
Subject: [PATCH] lib/idr: fix memory leak in ida_alloc_range() error path
Date: Thu, 12 Mar 2026 17:18:34 +0000	[thread overview]
Message-ID: <20260312171834.8837-1-objecting@objecting.org> (raw)

In ida_alloc_range(), if the XArray operation encounters an error
(e.g., -ENOSPC) during allocation, the function exits early via
return xas_error(&xas). However, if an intermediate `alloc` bitmap
was allocated via kzalloc() earlier in the function but the XArray
insertion failed, the error path returns without freeing `alloc`.

Reorder the error handling to ensure `alloc` is properly freed when
an XArray error occurs.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/idr.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/idr.c b/lib/idr.c
index 07098eb4ddc3..2ad96befa17a 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -460,10 +460,12 @@ int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max,
 		bit = min % IDA_BITMAP_BITS;
 		goto retry;
 	}
-	if (bitmap != alloc)
+	if (xas_error(&xas)) {
 		kfree(alloc);
-	if (xas_error(&xas))
 		return xas_error(&xas);
+	}
+	if (bitmap != alloc)
+		kfree(alloc);
 	return xas.xa_index * IDA_BITMAP_BITS + bit;
 alloc:
 	xas_unlock_irqrestore(&xas, flags);
-- 
2.34.1



                 reply	other threads:[~2026-03-12 17:18 UTC|newest]

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