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 468173C07A; Thu, 20 Aug 2026 15:10:43 +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=1787238644; cv=none; b=G1yS5XGsr2sJ+UJn6KqVHzDzBr3fHILb2GQxpxMvVZG6t0bIZ7WS9Fxz83O01qUwp4Rm2R6XqjG6q434zwUm/WtZzGgsfiKB1zkIP04tWhn7ouhDrNCsUYBSBAWFYlw3JH12AZ22A0BB4+sedDmGVvC0ttt6jt2nxXTECG3aQGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787238644; c=relaxed/simple; bh=JPxkxgzMONWMOkAR2kYqCj/rhfdugKpz/48YsX1S/LA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=paqxG85808uSQvqjdrpi1UjrrMapC0n7tf3Uq7jbPKQFEm5QkMH1uDF+95Qgk9ABrvlwa101FPViujtzDspyVeP6IbhSLkSJlYrhBP3QbD0HUlr81Y++yMQdl02dQBvgewgNxdvn4blsqmrWLIjY5EA4FGInDOuWgsMQct9UuSI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KtE8w3K4; 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="KtE8w3K4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FCF61F000E9; Thu, 20 Aug 2026 15:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787238643; bh=e4dvyILaff2oGAg+6m916mDV2MXs/caw4qCDZdAgGNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KtE8w3K4ijnPS08uCJS3QRPdHdbsYmTi2LeVlNzVp5yBNxF70//dkuvOmc3+VjJO0 DyVyQR3xvFZcX+Kyfgznw+9qBYN5J/+8dyE0G3+2IZRqFn42UCpNceUW2CpOnVTldL k6d4yGjsp+/1fiulevUaDXrDh0QlNLxmjFjW95II= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+d30aad27833a559defab@syzkaller.appspotmail.com, Aleksandr Nogikh , Takashi Sakamoto , Sasha Levin Subject: [PATCH 7.1 218/228] firewire: ohci: fix NULL pointer dereference in ar_context_release Date: Thu, 20 Aug 2026 16:56:00 +0200 Message-ID: <20260820145251.683961644@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145244.450574346@linuxfoundation.org> References: <20260820145244.450574346@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 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aleksandr Nogikh [ Upstream commit 42d217add8d80d6e7d9f58f80d11ea9b07ea113e ] During the error handling path of the driver's probe function, a NULL pointer dereference can occur in ar_context_release(). When pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping fails), the devres cleanup mechanism invokes release_ohci(). This function unconditionally calls ar_context_release() to clean up the asynchronous receive contexts. However, if ar_context_init() was not yet called, ctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by devres_alloc()). ar_context_release() immediately dereferences ctx->ohci to get the dev pointer before checking if the context was actually initialized, leading to a crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543 Call Trace: release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567 release_nodes drivers/base/devres.c:546 [inline] devres_release_all+0x1a8/0x260 drivers/base/devres.c:576 device_unbind_cleanup drivers/base/dd.c:597 [inline] really_probe+0x451/0xae0 drivers/base/dd.c:772 To fix this, move the assignment of the dev pointer after the !ctx->buffer check. If ctx->buffer is NULL, it indicates that the context was never successfully initialized and there is nothing to release, safely avoiding the dereference of the uninitialized ctx->ohci pointer. Fixes: 5716e58aecdd ("firewire: ohci: release buffer for AR req/resp contexts when managed resource is released") Assisted-by: Gemini:gemini-3.5-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+d30aad27833a559defab@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d30aad27833a559defab Link: https://syzkaller.appspot.com/ai_job?id=10a18617-7893-42dd-bf1c-cd49e19e95d9 Signed-off-by: Aleksandr Nogikh Link: https://lore.kernel.org/r/90c5db71-dd1f-4d46-b9d3-2f1046cbd5ea@mail.kernel.org Signed-off-by: Takashi Sakamoto Signed-off-by: Sasha Levin --- drivers/firewire/ohci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 8153d62c58f06..e947227e01acc 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -540,11 +540,13 @@ static void ar_context_link_page(struct ar_context *ctx, unsigned int index) static void ar_context_release(struct ar_context *ctx) { - struct device *dev = ctx->ohci->card.device; + struct device *dev; if (!ctx->buffer) return; + dev = ctx->ohci->card.device; + for (int i = 0; i < AR_BUFFERS; ++i) { dma_addr_t dma_addr = ctx->dma_addrs[i]; if (dma_addr) -- 2.53.0