From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Lin Subject: [PATCH v4] mmc: sdio: check the buffer address for sdio API Date: Tue, 7 Feb 2017 08:54:50 +0800 Message-ID: <1486428890-28187-1-git-send-email-shawn.lin@rock-chips.com> Return-path: Received: from lucky1.263xmail.com ([211.157.147.135]:33334 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752663AbdBGA5M (ORCPT ); Mon, 6 Feb 2017 19:57:12 -0500 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: linux-mmc@vger.kernel.org, Shawn Lin It's fine if the host driver use PIO mode to transfer the vmalloc area buffer but not for DMA mode. The sdio APIs haven't provide the capability to tell the caller whether it will use DMA to finish the IO transfer or not, so don't give the randomly insmoded sdio function driver the possibility to break the kernel. Also the APIs shouldn't take the liberty to do a copy for these cases and just kick out these requests should be enough. This issue is observed by doing insmod a downloaded wifi module driver and the kernel panic right away. Unfortunately we don't have the source code but adding this patch that it proves that the module driver was passing on a vmalloc area buffer for sdio APIs. It could very easy to be reproduced by writing a simple function module driver and insmod it, and panic log looks like: unsigned u8 __aligned(32) buf[PAGE_SIZE]; static int wifi_probe(struct sdio_func *func, const struct sdio_device_id *id) { sdio_claim_host(func); sdio_enable_func(func); sdio_memcpy_toio(func, 0x0, buf, 0x200); } [ 236.748210] wifi_probe: buf = 0xffffff8000a40b80 [ 236.748258] swiotlb_tbl_map_single: orig_addr = 0xfffffffff8c40b80, tlb_addr = 0xf7eae000 //I added log here [ 236.748276] Unable to handle kernel paging request at virtual address fffffffff8c40b80 [ 236.776486] pgd = ffffffc0b3417000 [ 236.776789] [fffffffff8c40b80] *pgd=00000000b3427003, *pud=00000000b3427003, *pmd=0000000000000000 [ 236.777601] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 236.778093] Modules linked in: drvtst(O+) [ 236.778463] CPU: 0 PID: 1918 Comm: insmod Tainted: G O 4.4.36 #25 [ 236.779096] Hardware name: Rockchip RK3399 Evaluation Board v3 edp (Android) (DT) [ 236.779753] task: ffffffc0e3db0c40 ti: ffffffc0b342c000 task.ti: ffffffc0b342c000 [ 236.780418] PC is at __memcpy+0x100/0x180 [ 236.780777] LR is at swiotlb_tbl_map_single+0x254/0x274 [ 236.781237] pc : [] lr : [] ... [ 236.941392] f460: 3d20726464615f67 6666666666783020 [ 236.941826] [] __memcpy+0x100/0x180 [ 236.942274] [] swiotlb_map_sg_attrs+0xa8/0x170 [ 236.942810] [] __swiotlb_map_sg_attrs+0x24/0x8c [ 236.943353] [] dw_mci_pre_dma_transfer.isra.16+0xf0/0x11c [ 236.943967] [] __dw_mci_start_request+0x17c/0x4d0 [ 236.944520] [] dw_mci_request+0xb8/0xf0 [ 236.945002] [] __mmc_start_request+0x9c/0xc0 [ 236.945520] [] mmc_start_request.part.17+0x100/0x11c [ 236.946097] [] mmc_wait_for_req+0x78/0x1a8 [ 236.946600] [] mmc_io_rw_extended+0x27c/0x2fc [ 236.947124] [] sdio_io_rw_ext_helper+0x1e4/0x238 [ 236.947670] [] sdio_memcpy_toio+0x24/0x2c [ 236.948169] [] wifi_probe+0xa8/0x198 [drvtst] [ 236.948708] [] sdio_bus_probe+0xb0/0x140 [ 236.949195] [] driver_probe_device+0x118/0x2b0 [ 236.949724] [] __driver_attach+0x64/0x90 [ 236.950212] [] bus_for_each_dev+0x80/0xb0 [ 236.950706] [] driver_attach+0x20/0x28 [ 236.951176] [] bus_add_driver+0xe8/0x1ec [ 236.951661] [] driver_register+0x98/0xe4 [ 236.952147] [] sdio_register_driver+0x24/0x2c [ 236.952675] [] wifi_sdio_init+0x30/0x68 [drvtst] [ 236.953241] [] wifi_drv_init+0xc/0x38 [drvtst] [ 236.953789] [] do_one_initcall+0x17c/0x198 [ 236.954293] [] do_init_module+0x60/0x1b8 [ 236.954779] [] load_module+0x1660/0x1a50 [ 236.955264] [] SyS_init_module+0x14c/0x180 [ 236.955765] [] el0_svc_naked+0x24/0x28 So the kernel crash since the vmalloc area buffer, on-stack buffer or the on-module buffer aren't physical continuous and swiotlb couldn't find the correct mapping address in fact. Anyway, don't give the chance to panic kernel by using sdio APIs. Signed-off-by: Shawn Lin --- Changes in v4: - fix build warning by gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 Changes in v3: - fix build issue reported by Kbuild Robot Changes in v2: - add new function to check the addr of vmalloc/module/stack drivers/mmc/core/sdio_io.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c index 406e5f0..4df7c6f 100644 --- a/drivers/mmc/core/sdio_io.c +++ b/drivers/mmc/core/sdio_io.c @@ -10,6 +10,7 @@ */ #include +#include #include #include #include @@ -298,6 +299,19 @@ unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz) } EXPORT_SYMBOL_GPL(sdio_align_size); +static int sdio_io_addr_sanity_check(void *buf) +{ +#if defined(CONFIG_MODULES) && defined(MODULES_VADDR) + unsigned long addr = (unsigned long)buf; + + if ((addr >= MODULES_VADDR && addr < MODULES_END) || + object_is_on_stack(buf)) + return 1; +#endif + return (is_vmalloc_addr(buf) || object_is_on_stack(buf)); + +} + /* Split an arbitrarily sized data transfer into several * IO_RW_EXTENDED commands. */ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write, @@ -307,7 +321,7 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write, unsigned max_blocks; int ret; - if (!func || (func->num > 7)) + if (!func || (func->num > 7) || sdio_io_addr_sanity_check(buf)) return -EINVAL; /* Do the bulk of the transfer using block mode (if supported). */ -- 1.9.1