From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2E19B3F8E04; Tue, 31 Mar 2026 16:54:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976099; cv=none; b=WsO6OJ9pP+K4t9axwn/Kq1J5WT7CbZyDP+PqjtJxyeu1LGNSKG5Zy64wUdKSvBdjV9JtvZ1ND34hmP/WRo4q8sfqH4VmmW9AL4T6hRBxHI1E72ouNAaxKmTRrtwvio7fW21I8kX3ZNcTYtRhUars0vzy6H3QuETHI99Ra4VN6l8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976099; c=relaxed/simple; bh=b2kWUpoZqOqd7rqFTsAAvl23QKewzGh0F3thdjC8w/Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hGHR49SeihWtW5Ty+4iwUDOzReNOBClknooUkg3xz8Gw9VDtRgocwZowQdVqdkyeVSDncDH/tE9MRxKDdDYo5iEZ1Oi/1XyMPrLnINun87wCuV6rNVpyGeu1EIjWdSU8OU4CTQSyze0WTvqpX++YtKFvLgAkQUVNOtHML1D98m4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lKi58gVs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="lKi58gVs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAB66C19423; Tue, 31 Mar 2026 16:54:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976099; bh=b2kWUpoZqOqd7rqFTsAAvl23QKewzGh0F3thdjC8w/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lKi58gVsbdZbwG09Ly9iPbANRbR7mqO0VKoH4m9lEW/E9rOerSyktWlE1cPwgXnbh Jn2QJoTHM51y5s5nPsajy1xCVMgwrmjVpw7aubLWVGKUCg0Jx7sAgIvmcHjedE2rq7 l1rUBgWiMME4pV71hU3FWNfckJT2G+5zN9lO0ELE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Breno Leitao , Jon Hunter , Thierry Reding , Mark Brown , Jianqiang kang Subject: [PATCH 6.12 205/244] spi: tegra210-quad: Protect curr_xfer check in IRQ handler Date: Tue, 31 Mar 2026 18:22:35 +0200 Message-ID: <20260331161749.322817589@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161741.651718120@linuxfoundation.org> References: <20260331161741.651718120@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Breno Leitao [ Upstream commit edf9088b6e1d6d88982db7eb5e736a0e4fbcc09e ] Now that all other accesses to curr_xfer are done under the lock, protect the curr_xfer NULL check in tegra_qspi_isr_thread() with the spinlock. Without this protection, the following race can occur: CPU0 (ISR thread) CPU1 (timeout path) ---------------- ------------------- if (!tqspi->curr_xfer) // sees non-NULL spin_lock() tqspi->curr_xfer = NULL spin_unlock() handle_*_xfer() spin_lock() t = tqspi->curr_xfer // NULL! ... t->len ... // NULL dereference! With this patch, all curr_xfer accesses are now properly synchronized. Although all accesses to curr_xfer are done under the lock, in tegra_qspi_isr_thread() it checks for NULL, releases the lock and reacquires it later in handle_cpu_based_xfer()/handle_dma_based_xfer(). There is a potential for an update in between, which could cause a NULL pointer dereference. To handle this, add a NULL check inside the handlers after acquiring the lock. This ensures that if the timeout path has already cleared curr_xfer, the handler will safely return without dereferencing the NULL pointer. Fixes: b4e002d8a7ce ("spi: tegra210-quad: Fix timeout handling") Signed-off-by: Breno Leitao Tested-by: Jon Hunter Acked-by: Jon Hunter Acked-by: Thierry Reding Link: https://patch.msgid.link/20260126-tegra_xfer-v2-6-6d2115e4f387@debian.org Signed-off-by: Mark Brown [ Minor conflict resolved. ] Signed-off-by: Jianqiang kang Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-tegra210-quad.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) --- a/drivers/spi/spi-tegra210-quad.c +++ b/drivers/spi/spi-tegra210-quad.c @@ -1351,6 +1351,11 @@ static irqreturn_t handle_cpu_based_xfer spin_lock_irqsave(&tqspi->lock, flags); t = tqspi->curr_xfer; + if (!t) { + spin_unlock_irqrestore(&tqspi->lock, flags); + return IRQ_HANDLED; + } + if (tqspi->tx_status || tqspi->rx_status) { tegra_qspi_handle_error(tqspi); complete(&tqspi->xfer_completion); @@ -1419,6 +1424,11 @@ static irqreturn_t handle_dma_based_xfer spin_lock_irqsave(&tqspi->lock, flags); t = tqspi->curr_xfer; + if (!t) { + spin_unlock_irqrestore(&tqspi->lock, flags); + return IRQ_HANDLED; + } + if (err) { tegra_qspi_dma_unmap_xfer(tqspi, t); tegra_qspi_handle_error(tqspi); @@ -1457,6 +1467,7 @@ exit: static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data) { struct tegra_qspi *tqspi = context_data; + unsigned long flags; u32 status; /* @@ -1474,7 +1485,9 @@ static irqreturn_t tegra_qspi_isr_thread * If no transfer is in progress, check if this was a real interrupt * that the timeout handler already processed, or a spurious one. */ + spin_lock_irqsave(&tqspi->lock, flags); if (!tqspi->curr_xfer) { + spin_unlock_irqrestore(&tqspi->lock, flags); /* Spurious interrupt - transfer not ready */ if (!(status & QSPI_RDY)) return IRQ_NONE; @@ -1491,7 +1504,14 @@ static irqreturn_t tegra_qspi_isr_thread tqspi->rx_status = tqspi->status_reg & (QSPI_RX_FIFO_OVF | QSPI_RX_FIFO_UNF); tegra_qspi_mask_clear_irq(tqspi); + spin_unlock_irqrestore(&tqspi->lock, flags); + /* + * Lock is released here but handlers safely re-check curr_xfer under + * lock before dereferencing. + * DMA handler also needs to sleep in wait_for_completion_*(), which + * cannot be done while holding spinlock. + */ if (!tqspi->is_curr_dma_xfer) return handle_cpu_based_xfer(tqspi);