From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4C62031CA4E; Fri, 7 Aug 2026 14:54:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786114457; cv=none; b=YkIJ9cS3UTXBnkcjzyTxfZnGqTLZMAuHVoeJ283wW8GOdJAAl7i3RDMVkF6oElSdXsKkmAp1pab0ZTjGZIzgsPDT62ld2jHonuxRXbSBYvP5C7LhjPKFOpGxVqMwjhx5+vhu6bXD81fFyRot+PORvxVK+j9bCFqCCjyaSAlGMBc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786114457; c=relaxed/simple; bh=JmALDYKC6E7cvctMgCA602nt9KFV4tBtnITgLxjESJ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=flgjBmy/1yyjToCy+RxJzuB594/sG+S/27+rPcntMo8p0cMr5Apz6S1knyNruGfuJhu3nXGUkCOliDFw/r0JCAb+OTBOO/gDRxqdRkkRKZ3oIfA5M53D33jqAvJMWWASoNeQ0saH7NKaYZ6fSccP98qL6Q2rmoSH4OJf9ivYHFE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=x9tnaTJb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="x9tnaTJb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3D081F000E9; Fri, 7 Aug 2026 14:54:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786114456; bh=heGXFFyCbP9S/yrBKXDGNbuHsOW3TrI/jIZ2fHJbvnc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=x9tnaTJbBDaYtD7Lf/xIJIPdFYYTXFJ1gOuCR9uEliIDa1JBceEItZBNZtSDkuJqF YlgKWTSxFywyEwLczpQfYaq9uSjRwXMuoiIqCskwt3VcUT9E5g5+HDixB+ILGhuooG wJpi7bOLBo02wmdwMOqi79K062OHYrd/DHn0anqA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Liem , Frank Li , Carlos Song , Andi Shyti Subject: [PATCH 6.12 225/337] i2c: imx: Fix slave registration race and error handling Date: Fri, 7 Aug 2026 16:37:08 +0200 Message-ID: <20260807143423.433154922@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143418.516897842@linuxfoundation.org> References: <20260807143418.516897842@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liem commit d64ec362c369bbc33833f7936d5f3a706b0d5c45 upstream. In i2c_imx_reg_slave(), the slave pointer was assigned before pm_runtime_resume_and_get(). If pm_runtime_resume_and_get() failed, the error path returned without clearing i2c_imx->slave, leaving it non-NULL and causing all subsequent registration attempts to fail with -EBUSY. Additionally, because this driver uses a shared IRQ, the interrupt handler i2c_imx_isr() can execute concurrently and, after acquiring slave_lock, dereference i2c_imx->slave. The previous fix attempt added a lockless i2c_imx->slave = NULL on the error path, but that could race with the ISR under the lock and still cause a NULL pointer dereference. Fix both issues by deferring the assignment of i2c_imx->slave and i2c_imx->last_slave_event to after a successful resume, and by performing the assignment inside the slave_lock critical section. This guarantees that the slave pointer is never left stale on the error path and is always valid when observed by the interrupt handler. Fixes: f7414cd6923f ("i2c: imx: support slave mode for imx I2C driver") Signed-off-by: Liem Cc: # v5.11+ Reviewed-by: Frank Li Acked-by: Carlos Song Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260629023829.152651-2-liem16213@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-imx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -866,9 +866,6 @@ static int i2c_imx_reg_slave(struct i2c_ if (i2c_imx->slave) return -EBUSY; - i2c_imx->slave = client; - i2c_imx->last_slave_event = I2C_SLAVE_STOP; - /* Resume */ ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent); if (ret < 0) { @@ -876,6 +873,11 @@ static int i2c_imx_reg_slave(struct i2c_ return ret; } + scoped_guard(spinlock_irqsave, &i2c_imx->slave_lock) { + i2c_imx->slave = client; + i2c_imx->last_slave_event = I2C_SLAVE_STOP; + } + i2c_imx_slave_init(i2c_imx); return 0;