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 5C6127E for ; Sun, 22 Jan 2023 15:08:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6FE8C433D2; Sun, 22 Jan 2023 15:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674400087; bh=x3zuXH2FBxcWrid4yJnZf43UQqQClid62ottuSmy138=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nHdqL4LKrVCDB8WzEVhw+gTyO4j9Fv/G0+/Oy4+ZOgv+GRf6mNw1BRX61U+oUfCJ0 QA+DHoyXOY804PhtUYxmCCVgJtqO/m2C/QXv0NIJAUzYVZrL7TqanGN063xHKZCTm6 Nf8E7wV3ir8O03907PzaGSilwXz/xoF7z7GApym8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Shawn.Shao" , Vinod Koul Subject: [PATCH 4.19 05/37] Add exception protection processing for vd in axi_chan_handle_err function Date: Sun, 22 Jan 2023 16:04:02 +0100 Message-Id: <20230122150219.804139316@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230122150219.557984692@linuxfoundation.org> References: <20230122150219.557984692@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Shawn.Shao commit 57054fe516d59d03a7bcf1888e82479ccc244f87 upstream. Since there is no protection for vd, a kernel panic will be triggered here in exceptional cases. You can refer to the processing of axi_chan_block_xfer_complete function The triggered kernel panic is as follows: [ 67.848444] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060 [ 67.848447] Mem abort info: [ 67.848449] ESR = 0x96000004 [ 67.848451] EC = 0x25: DABT (current EL), IL = 32 bits [ 67.848454] SET = 0, FnV = 0 [ 67.848456] EA = 0, S1PTW = 0 [ 67.848458] Data abort info: [ 67.848460] ISV = 0, ISS = 0x00000004 [ 67.848462] CM = 0, WnR = 0 [ 67.848465] user pgtable: 4k pages, 48-bit VAs, pgdp=00000800c4c0b000 [ 67.848468] [0000000000000060] pgd=0000000000000000, p4d=0000000000000000 [ 67.848472] Internal error: Oops: 96000004 [#1] SMP [ 67.848475] Modules linked in: dmatest [ 67.848479] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.100-emu_x2rc+ #11 [ 67.848483] pstate: 62000085 (nZCv daIf -PAN -UAO +TCO BTYPE=--) [ 67.848487] pc : axi_chan_handle_err+0xc4/0x230 [ 67.848491] lr : axi_chan_handle_err+0x30/0x230 [ 67.848493] sp : ffff0803fe55ae50 [ 67.848495] x29: ffff0803fe55ae50 x28: ffff800011212200 [ 67.848500] x27: ffff0800c42c0080 x26: ffff0800c097c080 [ 67.848504] x25: ffff800010d33880 x24: ffff80001139d850 [ 67.848508] x23: ffff0800c097c168 x22: 0000000000000000 [ 67.848512] x21: 0000000000000080 x20: 0000000000002000 [ 67.848517] x19: ffff0800c097c080 x18: 0000000000000000 [ 67.848521] x17: 0000000000000000 x16: 0000000000000000 [ 67.848525] x15: 0000000000000000 x14: 0000000000000000 [ 67.848529] x13: 0000000000000000 x12: 0000000000000040 [ 67.848533] x11: ffff0800c0400248 x10: ffff0800c040024a [ 67.848538] x9 : ffff800010576cd4 x8 : ffff0800c0400270 [ 67.848542] x7 : 0000000000000000 x6 : ffff0800c04003e0 [ 67.848546] x5 : ffff0800c0400248 x4 : ffff0800c4294480 [ 67.848550] x3 : dead000000000100 x2 : dead000000000122 [ 67.848555] x1 : 0000000000000100 x0 : ffff0800c097c168 [ 67.848559] Call trace: [ 67.848562] axi_chan_handle_err+0xc4/0x230 [ 67.848566] dw_axi_dma_interrupt+0xf4/0x590 [ 67.848569] __handle_irq_event_percpu+0x60/0x220 [ 67.848573] handle_irq_event+0x64/0x120 [ 67.848576] handle_fasteoi_irq+0xc4/0x220 [ 67.848580] __handle_domain_irq+0x80/0xe0 [ 67.848583] gic_handle_irq+0xc0/0x138 [ 67.848585] el1_irq+0xc8/0x180 [ 67.848588] arch_cpu_idle+0x14/0x2c [ 67.848591] default_idle_call+0x40/0x16c [ 67.848594] do_idle+0x1f0/0x250 [ 67.848597] cpu_startup_entry+0x2c/0x60 [ 67.848600] rest_init+0xc0/0xcc [ 67.848603] arch_call_rest_init+0x14/0x1c [ 67.848606] start_kernel+0x4cc/0x500 [ 67.848610] Code: eb0002ff 9a9f12d6 f2fbd5a2 f2fbd5a3 (a94602c1) [ 67.848613] ---[ end trace 585a97036f88203a ]--- Signed-off-by: Shawn.Shao Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230112055802.1764-1-shawn.shao@jaguarmicro.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -551,6 +551,11 @@ static noinline void axi_chan_handle_err /* The bad descriptor currently is in the head of vc list */ vd = vchan_next_desc(&chan->vc); + if (!vd) { + dev_err(chan2dev(chan), "BUG: %s, IRQ with no descriptors\n", + axi_chan_name(chan)); + goto out; + } /* Remove the completed descriptor from issued list */ list_del(&vd->node); @@ -565,6 +570,7 @@ static noinline void axi_chan_handle_err /* Try to restart the controller */ axi_chan_start_first_queued(chan); +out: spin_unlock_irqrestore(&chan->vc.lock, flags); }