From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from xmbghk7.mail.qq.com (xmbghk7.mail.qq.com [43.163.128.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31DF279F2; Wed, 27 Aug 2025 11:51:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=43.163.128.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756295481; cv=none; b=XIUPPRUmJKTGo13gXttlkqU8UmkK+STXDLN5TtWEUzucpbDrBnsnb4bbZvhdlrzaby+t0bmq0axOoQcE1j3ZUccN/L8SSNPb93IEX88I8lW5eJt8IqScyBANyvB6sbFCKp1a/yApKpw9ELkIot0uRSRqRuGmDKJ3sLLE58WIvQ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756295481; c=relaxed/simple; bh=ccyX1PDsjLelMFjOfiaiMPG+qkk4GLlT/rYXDlrW0KU=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=qwJizFcc3mj3FUSmVFVIcjyOKleqrbtMBB6t6F9q5W1SPGHjSZACsRoYmNVWyh+4z+WqGUBuIlu/Qozf0oLvc2Dt3xqMU551w0pHvkE0eLsxiI31S8wYLSy08yY5sOd+mNOC606/OISgp6IJV2QpIx4Ld6QM+GEyNHWunFe9vao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=x2aQd+Fe; arc=none smtp.client-ip=43.163.128.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="x2aQd+Fe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1756295476; bh=SeX1GYV2aQwc6O4xvX38s0OKdpYFk5AKG8oI2cIJdqE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=x2aQd+FeU5/F1nLPe8y9aMZfM9m8Mhi61fhu497J8UY/lDLZ6OWR40MsfzPwTEVy+ s/k9+lOXFrlsFAL5VF71T/TBXE+IF5QwczvlyMRV2N+Zop7MlziCqDU+Z2KBV3n6Ya +5mfqdzJxMvTpelOMUZrsTTOZMgCm7Kc+a3+r3WA= Received: from nebula-bj.localdomain ([223.104.40.195]) by newxmesmtplogicsvrszc43-0.qq.com (NewEsmtp) with SMTP id B488E43B; Wed, 27 Aug 2025 19:45:08 +0800 X-QQ-mid: xmsmtpt1756295108trorwj4bz Message-ID: X-QQ-XMAILINFO: N6IfSeM/PG+tJkJouisOQ7aTCUC1nM2EvWU8+pRyPsIQSZuXbpl8r1uFQVEIRX ikML9JKhepNZqOqi2h5IkbV9n+YmAGkl+N0k69HsZmJUwL7a55NkUgEMTuOV+/frZI8JHPPNmUx2 3OWJKADbDB7Dyuy7+bLWktH1ihhe1RO/CO5v9e5vHcDmHC5HCMPsVPqJc3bdjR1x0lUkpkv8/gx4 gQj3YQ7D49P++5lWDyGwbWfD62O7nKLWTdgzb3dIr+NR2WNDa9KWCPCDwdBkUp592suTV4bJxbp9 /GEMgfjXWRm5afA886kJgsrxTrYepKkwNPfO/6QF6YS7LJ5VmbTXOtTqq0uMgl0tDnU+SJVstlnC VOdN3FLi9kCUPJhfIcR/SZQqGBJZfJZmvk/0TtfvaSUXcl0XKJRtNsacBhgUHD3OrP1yUE3J5gbo kX9DFIhBfWBFRaQGQ27iRuKFV+VwUtDPeCzP10datidfTFOEYA3gVYd5KClxSi+OcM1tZfyWLsr5 bYr/zcRlgUnwTeOrTMYLxeHFXT5+69tGvthogPlPKQvhmRopaM2SwQpjv6yncIrQxiyYCrBu0Ug0 tYodv+A380VsaxY+kGPOmbf21ZKC2A0vspuIsCNTKQ7DZQAKzlfMezhHlalqunIslD5Vij+37rrw yhfkU4AEh9jDGHhNavPbawpa+A4Oy9bZJdH5awUtQ6m70+QPqMn1MHrDlix9uWMPqusJ2cFbnKNw BIzC0VXGcXtwKrMQwjO0Fm8aq8N/rcGbpHIGHiBmwGhV29oc/SgreuS7iv5F0lOAOTqF7js+DKeB MDkmGdzaDsxWIXGrCvUzrXhVBQC08u6MA70y33JHrV1+nDp25Tysu+I9n6H+7vKe6mZDWNJoTC0B vZUtvpXJOQBtdJCda4fKUHGaFz0DPyW6WU0onluR18lnk8H3D7FMWEV9og+ylzO6eK1AvnB945eq xTV6ECDPQqLHnwOm1UhWjdvthggSaCXDOWWXAI6aaIjvjS3Q4AQ38kNwYV4TOo8KlT9oswsWd6tF U3XTFxoZrlaej5zaGkOdFwBZTT5E9OunsFWlxarUhp8EZTNTZ7B8Fe4/6+CBnCU558eAmkpRQGGV /xiBHyrwSfw5VeybOjUkYW9N4Xpf+mEq5KiWXe667wYty5LITZlHHwPz7L+FJajJjIHfeuBc5Ggs hQem0= X-QQ-XMRINFO: Nq+8W0+stu50PRdwbJxPCL0= From: Qingyue Zhang To: axboe@kernel.dk Cc: io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, Qingyue Zhang , Suoxing Zhang Subject: [PATCH 2/2] io_uring/kbuf: fix infinite loop in io_kbuf_inc_commit() Date: Wed, 27 Aug 2025 19:44:53 +0800 X-OQ-MSGID: <20250827114453.368894-1-chunzhennn@qq.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250827114339.367080-1-chunzhennn@qq.com> References: <20250827114339.367080-1-chunzhennn@qq.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In io_kbuf_inc_commit(), buf points to a user-mapped memory region, which means buf->len might be changed between importing and committing. Add a check to avoid infinite loop when sum of buf->len is less than len. Co-developed-by: Suoxing Zhang Signed-off-by: Suoxing Zhang Signed-off-by: Qingyue Zhang --- io_uring/kbuf.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 81a13338dfab..80ffe6755598 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -34,11 +34,12 @@ struct io_provide_buf { static bool io_kbuf_inc_commit(struct io_buffer_list *bl, int len) { + struct io_uring_buf *buf, *buf_start; + + buf_start = buf = io_ring_head_to_buf(bl->buf_ring, bl->head, bl->mask); while (len) { - struct io_uring_buf *buf; u32 this_len; - buf = io_ring_head_to_buf(bl->buf_ring, bl->head, bl->mask); this_len = min_t(u32, len, buf->len); buf->len -= this_len; if (buf->len) { @@ -47,6 +48,10 @@ static bool io_kbuf_inc_commit(struct io_buffer_list *bl, int len) } bl->head++; len -= this_len; + + buf = io_ring_head_to_buf(bl->buf_ring, bl->head, bl->mask); + if (unlikely(buf == buf_start)) + break; } return true; } -- 2.48.1