From nobody Tue Sep 29 02:02:26 2026 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F8D6439015 for ; Thu, 13 Aug 2026 14:29:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786631379; cv=none; b=L8M2pJedWn2KxUzU9GYznvoaEy9DKKszL5koxKXjsKakuPCazU+Gmm7Zf3tmu4//Do38THyQ/kKTqMBEjyuI3umBY+pS480FyVNp+oXwtEsAVkQYJxZJQ0dTcKchY/V5UvnFQDrTOr2U7efAYKnyX8Fd38z3sQmy3nc4u//qaY0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786631379; c=relaxed/simple; bh=fn/XLC+6m5VzN+X4PVvs9fE6+rYoplaOpcOerR0lGQY=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=cPBj8EGGJTMpDZqWr7j3v6o2ep8N9OKbjBcth0Io0vCfzZRBLTmd75ehO1pCfpsnPa8oNigj0aTComhuomqvhyMu1jybBGFMYg6Mlhzg9HOhfWZPPl8bTWD3jbKimiAcQjz3PHVB5D3ItK+53ytvL9w5i+vp7ZdoHAW1SPpBgt8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Bna/qP7D; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bna/qP7D" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-2cf6d65d8a7so488755ad.0 for ; Thu, 13 Aug 2026 07:29:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786631378; x=1787236178; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=slSc0BawJ2HB7BNu1jpFArTWF6e11TBXo3Cg8xFP3/0=; b=Bna/qP7Dn4vsaowz66ctaWxiu7U9+zG1TAh5U1qqXblonmyFMviDpjTSRL387kDx0g YW4+l2uySMrkMFsMF/+rSSrBM9w8VS2ZCgjCbmcE35AOkL0RZuJOr4A5sF7UlLx8EK1r GXh4KeQUuCJg/W7YaRzOlhKdaZj3l8uG3qrFavubQ7acgaMUbr1w0wPcVij+8O3UBGRH S3oJ5e5hSG4T5SuOIUVgPr+GRHpmVOUKC00yX6Hx5XySDjLgElmqeT081OROYEYqoOWS M69KGI+WwgQUKAh4D2FbJ+0mlYjpUqCjCgEW8U1kQAqIR1p3E2LT9XKjdQXZoEX8ubSS 5ZsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786631378; x=1787236178; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=slSc0BawJ2HB7BNu1jpFArTWF6e11TBXo3Cg8xFP3/0=; b=EKKKYV4zziRIA24Y3Da7xom7tzWTqwpg42SAhi8Ojfb6vhv6vCIeso0ShPs01vVzvL E0LJDL+q/iEIUa766v9rCTKXu3qTmcpo6MXFW43jT/5mrxu6QIeGhagYGz5LoLxza0DX WBQDLN7jZB/V892ocS6jY4i9yT0bhhiwrxF5De5/6rc9WjzSxLuJDwbTlRp5zMLnd6pi /kVDFOuTTaEScQDNaVwkq/OkrcIjP45BiuLQ4IUaVWmKUzSPFFF2omQcchcdSzIAttwn mETCCwmFkHjxBw1hYQsh0k9fVZB+qRywSGvq2vGK6GZJNqVrkg13kqFdxAmYHbz2F7Un EHEQ== X-Forwarded-Encrypted: i=1; AHgh+Rq/dN2Zh+9BfshoKfCm5fjQ02hiRyRSGUCCSQdoPeNREipH5jvmjBOQkjqb3xX9xD69ZsRsIp+lmzLwiH4=@vger.kernel.org X-Gm-Message-State: AOJu0YwxwPvPE51EMWQbUFbBtqJydUvhz0JY2eYHbJUgzG0I1hUe0HAt M16E3reCBOKIZQnKB8v2CuVQ13bDPO/8N7twsDYNB4IRLnnyAN26SQ7+ X-Gm-Gg: AR+sD11lB6MHUV16M87zvsN/wq9uq7jY/LPAbmU7K+T2XVq4BT0iD0vmdfjEap1pvYa deUcyNUuZskfCc4zfkAlmyhjRvjrOkfcRsSFZG1hxg+iuEz+VqpXc2VcwYSnkr8Etdumrenj5se 8FqHCV6pgqJad8erypxHPW34kIWkdr3qMAjqaBdc/IHeChJDbovoI64ghGy7Pwug7ViacLxI8Hr aUov4paKajAtYKSEn9VmxTvbbvMwreZZLitWv79S6AyZXadCePcOUZeYmBI2F95kfI2wspXgGkC 6Thlw9vw1Z5DGzqF3mwzC7iyQX0pt60Js2qKA8mxmiOwZPvdij490DAOHrQsk4eHeqFzyzPIlFd Hfee5x32PB62JYwKBVqeWwNCo+YIZNz0KABQRe9yYSOXLkT2BgrCn5sh2r2AiIvVUee2hbwgheh 5Dqk6r3XwnVWtgnFR/2t2pxaRQDAxoLUVvh2XmNppZ1qlZkQHIiWSul6mRSchuS3z6kr/FvrXS8 g== X-Received: by 2002:a17:903:1b46:b0:2ca:d91d:d3a7 with SMTP id d9443c01a7336-2d37d884e0bmr78727825ad.10.1786631377516; Thu, 13 Aug 2026 07:29:37 -0700 (PDT) Received: from localhost.localdomain ([47.100.192.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2d37c499befsm10468405ad.66.2026.08.13.07.29.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Aug 2026 07:29:37 -0700 (PDT) From: Yang Wen To: linkinjeon@kernel.org, sj1557.seo@samsung.com Cc: yuezhang.mo@sony.com, exfat@lists.linux.dev, linux-kernel@vger.kernel.org, Yang Wen Subject: [PATCH] exfat: keep FITRIM within the requested range Date: Thu, 13 Aug 2026 22:29:19 +0800 Message-Id: <20260813142919.812744-1-anmuxixixi@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" exfat_find_free_bitmap() searches the entire allocation bitmap and may wrap around to its beginning. exfat_trim_fs() does not verify that the returned cluster is still within the requested FITRIM range. As a result, a partial FITRIM operation may discard free clusters outside the user-specified range and report a trimmed length larger than the requested length. Validate each returned cluster against the requested range and stop the search when it wraps around or passes the range end. Signed-off-by: Yang Wen --- fs/exfat/balloc.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index e66ebf899778..c0ddd522c1e1 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -340,14 +340,27 @@ int exfat_trim_fs(struct inode *inode, struct fstrim_= range *range) mutex_lock(&sbi->bitmap_lock); =20 trim_begin =3D trim_end =3D exfat_find_free_bitmap(sb, clu_start); - if (trim_begin =3D=3D EXFAT_EOF_CLUSTER) + /* + * exfat_find_free_bitmap() may wrap around to the beginning of + * the bitmap. Reject a cluster outside the requested range. + */ + if (trim_begin =3D=3D EXFAT_EOF_CLUSTER || + trim_begin < clu_start || trim_begin > clu_end) goto unlock; =20 - next_free_clu =3D exfat_find_free_bitmap(sb, trim_end + 1); - if (next_free_clu =3D=3D EXFAT_EOF_CLUSTER) - goto unlock; + for (;;) { + if (trim_end >=3D clu_end) + break; + + next_free_clu =3D exfat_find_free_bitmap(sb, trim_end + 1); + /* + * Stop if the search wrapped around or moved beyond the requested + * FITRIM range. + */ + if (next_free_clu =3D=3D EXFAT_EOF_CLUSTER || + next_free_clu <=3D trim_end || next_free_clu > clu_end) + break; =20 - do { if (next_free_clu =3D=3D trim_end + 1) { /* extend trim range for continuous free cluster */ trim_end++; @@ -368,17 +381,11 @@ int exfat_trim_fs(struct inode *inode, struct fstrim_= range *range) trim_begin =3D trim_end =3D next_free_clu; } =20 - if (next_free_clu >=3D clu_end) - break; - if (fatal_signal_pending(current)) { err =3D -ERESTARTSYS; goto unlock; } - - next_free_clu =3D exfat_find_free_bitmap(sb, next_free_clu + 1); - } while (next_free_clu !=3D EXFAT_EOF_CLUSTER && - next_free_clu > trim_end); + } =20 /* try to trim remainder */ count =3D trim_end - trim_begin + 1; --=20 2.34.1