From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f49.google.com (mail-pj1-f49.google.com [209.85.216.49]) (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 864A43ED5CA for ; Wed, 22 Apr 2026 14:42:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776868955; cv=none; b=sFaUJkWQHz6zSD+hfG6/pVqYF2t8Tr14P5kLJdohZ3QVdtlg6jsgwRJ5YIp9fZc6r6Ehfy03IRjayLMTT/LU7Vs4YDpiKe8H8tL2TcD5zetuSShFn78lZQpZ4moA8DsqY12tnKT2d8oYJzztV4m+wiErox/LFRCr71PVCXJ+et0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776868955; c=relaxed/simple; bh=6dGN6Sq4pulKWzbvWVOYJFY20pxbzEfT1MRlfUCn07E=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XTEW/F9b+HGEafhhTCO8eJsTwVj6XxvIWFb/RR43FBYmv+Patw+ANph9TKbKJS/0D/+5UjzuMbhvr3ye0e/NTHlIvwtpPbMl8iVdZVmv6t2s7tlVZ61Udc14BauIMZergRenueS5HFVQRU4NQ37kyzm6zGRQ+PblqOh9n5DyFac= 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=Q6vQOg1G; arc=none smtp.client-ip=209.85.216.49 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="Q6vQOg1G" Received: by mail-pj1-f49.google.com with SMTP id 98e67ed59e1d1-35da2d35eccso3917038a91.0 for ; Wed, 22 Apr 2026 07:42:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1776868953; x=1777473753; 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; bh=6BHaNKO4Vutd56sTBzf6LEct1U2PUWECXwrtGsxsQdI=; b=Q6vQOg1GD6sM9OURS7LFyoJU7tLASwZrHSIKTgqM/SNX1LqY0LFVtiLNFzIG3Q9Sbn Fe9nO8iZNPmjrZWvg23v1Nv3YWAOq6+47jt73IFZng0pcJM3Tp6LMRsr6NfAxOslt+Rg na4o/MdWZnza+XX616h7vvUGOfh3HEpsBxlIUVIPvoea6Xc5bN0wchDBScKn4RpHXoqe izK/Z+Fol7xq+jdLKRC/OjXecxOHozTgcF33Ey0bpozHfOf0o9+AYGq2/Jdoqu5Unz0i rXLLBUq8cNq14ZDFRgfSg+hUUkaeINycdKZtRmGyUl9SeUw/OTaMwiW5fHzyMBYshH7Y tvvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776868953; x=1777473753; 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; bh=6BHaNKO4Vutd56sTBzf6LEct1U2PUWECXwrtGsxsQdI=; b=TA0NJeq/B7o+d8kcDuEyIJKX74PLfYELH8N0iXVmWII6OMLNK/3nW8vUFFQJB84qLg BJV4fLRHTHEAxLGfBkQ06q9vFcAOzvNF4nn8oxxYDNHSrjLigXWjLldmaqzUISrUQrmd WcLPZjhIFDWeTfj4sI1e+iBiXut1aHMZQONEv08lucEgSuMr81VP8TmJgz6k7QKgDh/c EVVm/hLJqx3pOd0X+Sktbdn9tF/tSlvm1OOg0vBezu3WyYV7audLkvK3mMKOrTLXNCKg CY09lZ5YPwEyLJfHRNAk73snDvtCpRrOlLpWGG5SmSeaIl7ieu9G1rax/qEK8K6M9ZKy 2pSQ== X-Forwarded-Encrypted: i=1; AFNElJ8hSMCGsqzL0ergj8vHXDD2z7pVLm0vpbQVTdqLqh5QxrW70wonfTa3aPFsyikoP5Y+FRjnZj8=@vger.kernel.org X-Gm-Message-State: AOJu0YzqGcwZ9+M9G0hc3t1vaZKY0WUsLiYWbm8XX/46V0abNpkrlAa4 /Bs4T7j8XaTHEwrboigbNxi/lzl9bcssRowJ5dvN4gycWvextkOg2G+R X-Gm-Gg: AeBDieveDly0W/s/GnskpFduyEu2RK7JK2wptd0CRXjly5niVz0u2MPJQ9Guv4bvsw3 k+mUpCrQLCe8P6C8Y1zFKFJv2Msn9A6g9NY10BwX6CluWyzreuI6/M549x+tT4OvglUCtZan+M5 +7XRnDwCpFNQatvx+G0enI3H8XqBTeYsijHEG2fe972lRllXuyWUgqbE2HnLNhCFsoRu1QAKxov Y4CQNXdqVfbDFTcVQ3wr7mv7fhzJeLZe/hHxZgn9v8ca7Yowew0iWhILP9S1sNv+wAP7xc3pC65 3ZGwpNpMwA4Hl1Or+aGf2/3zRqY3i5nfjLleEUq1at+BynLRlSNj+NEyOwAKwtuS6h/7Cu3Cy3I CCmqXOCXoXV2TVgyW3LTqGU2vlg37SUqJB3Hw+OHFWWjIeS3jdKVHjY8dGQPl6NRfBCO9+fpOSx wxIEI59IcvVRZUV/ZMcW+U8ApBPS3ZNpbpUMReTwXSBUr9c/cEuRmJOTB2bqpalFcZO5kIGm9E4 V1R8n9Fy9W4C/H8hg== X-Received: by 2002:a17:903:17cb:b0:2b4:6083:6c15 with SMTP id d9443c01a7336-2b5fa055a6bmr214881525ad.41.1776868952844; Wed, 22 Apr 2026 07:42:32 -0700 (PDT) Received: from deepanshu-kernel-hacker.. ([2405:201:682f:383f:3191:a257:32a3:b02c]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2b5fab20d33sm177878725ad.63.2026.04.22.07.42.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Apr 2026 07:42:32 -0700 (PDT) From: Deepanshu Kartikey To: mchehab@kernel.org Cc: kees@kernel.org, peda@axentia.se, wsa@kernel.org, crope@iki.fi, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Deepanshu Kartikey , stable@vger.kernel.org, syzbot+019ced393ab913002b75@syzkaller.appspotmail.com Subject: [PATCH] media: rtl2832: fix use-after-free in rtl2832_remove() Date: Wed, 22 Apr 2026 20:12:21 +0530 Message-ID: <20260422144221.25544-1-kartikey406@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit cancel_delayed_work_sync() is called before i2c_mux_del_adapters() in rtl2832_remove(). While the cancel waits for any running instance of i2c_gate_work to finish, it does not prevent the timer from being rescheduled by a concurrent thread. During probe, the r820t_attach() call attempts I2C transfers through the mux adapter. These transfers go through i2c_mux_master_xfer(), which calls rtl2832_deselect() after the transfer completes, rescheduling i2c_gate_work via schedule_delayed_work(). If this transfer is still in flight when rtl2832_remove() runs, rtl2832_deselect() can reschedule i2c_gate_work after it has been cancelled, causing a use-after-free when kfree(dev) is called. Fix this by calling i2c_mux_del_adapters() before cancel_delayed_work_sync(). Once the mux adapter is unregistered, no new I2C transfers can go through it, so rtl2832_deselect() can no longer reschedule i2c_gate_work. The subsequent cancel_delayed_work_sync() is then guaranteed to be final. Fixes: cddcc40b1b15 ("[media] rtl2832: convert to use an explicit i2c mux core") Cc: stable@vger.kernel.org Reported-by: syzbot+019ced393ab913002b75@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=019ced393ab913002b75 Signed-off-by: Deepanshu Kartikey --- v2: - Fix Signed-off-by email address (lowercase k) - Add Cc: stable@vger.kernel.org for stable backport --- drivers/media/dvb-frontends/rtl2832.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c index d8e1546aea5e..9898f729304a 100644 --- a/drivers/media/dvb-frontends/rtl2832.c +++ b/drivers/media/dvb-frontends/rtl2832.c @@ -1115,10 +1115,10 @@ static void rtl2832_remove(struct i2c_client *client) dev_dbg(&client->dev, "\n"); - cancel_delayed_work_sync(&dev->i2c_gate_work); - i2c_mux_del_adapters(dev->muxc); + cancel_delayed_work_sync(&dev->i2c_gate_work); + regmap_exit(dev->regmap); kfree(dev); -- 2.43.0