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 : [<ffffff80083579c0>] lr : [<ffffff800837cf70>]
...
[ 236.941392] f460: 3d20726464615f67 6666666666783020
[ 236.941826] [<ffffff80083579c0>] __memcpy+0x100/0x180
[ 236.942274] [<ffffff800837dc18>] swiotlb_map_sg_attrs+0xa8/0x170
[ 236.942810] [<ffffff800809359c>] __swiotlb_map_sg_attrs+0x24/0x8c
[ 236.943353] [<ffffff800871113c>]
dw_mci_pre_dma_transfer.isra.16+0xf0/0x11c
[ 236.943967] [<ffffff80087129cc>] __dw_mci_start_request+0x17c/0x4d0
[ 236.944520] [<ffffff80087132e0>] dw_mci_request+0xb8/0xf0
[ 236.945002] [<ffffff80086f8b44>] __mmc_start_request+0x9c/0xc0
[ 236.945520] [<ffffff80087ae0e8>]
mmc_start_request.part.17+0x100/0x11c
[ 236.946097] [<ffffff80086f9c74>] mmc_wait_for_req+0x78/0x1a8
[ 236.946600] [<ffffff800870421c>] mmc_io_rw_extended+0x27c/0x2fc
[ 236.947124] [<ffffff8008705800>] sdio_io_rw_ext_helper+0x1e4/0x238
[ 236.947670] [<ffffff8008705954>] sdio_memcpy_toio+0x24/0x2c
[ 236.948169] [<ffffff8000a40108>] wifi_probe+0xa8/0x198 [drvtst]
[ 236.948708] [<ffffff8008704734>] sdio_bus_probe+0xb0/0x140
[ 236.949195] [<ffffff80084bfd6c>] driver_probe_device+0x118/0x2b0
[ 236.949724] [<ffffff80084bff68>] __driver_attach+0x64/0x90
[ 236.950212] [<ffffff80084bee18>] bus_for_each_dev+0x80/0xb0
[ 236.950706] [<ffffff80084bf8ac>] driver_attach+0x20/0x28
[ 236.951176] [<ffffff80084bf45c>] bus_add_driver+0xe8/0x1ec
[ 236.951661] [<ffffff80084c0afc>] driver_register+0x98/0xe4
[ 236.952147] [<ffffff8008704580>] sdio_register_driver+0x24/0x2c
[ 236.952675] [<ffffff8000a40228>] wifi_sdio_init+0x30/0x68 [drvtst]
[ 236.953241] [<ffffff8000a4400c>] wifi_drv_init+0xc/0x38 [drvtst]
[ 236.953789] [<ffffff8008082ba4>] do_one_initcall+0x17c/0x198
[ 236.954293] [<ffffff800815e564>] do_init_module+0x60/0x1b8
[ 236.954779] [<ffffff80081150f0>] load_module+0x1660/0x1a50
[ 236.955264] [<ffffff800811562c>] SyS_init_module+0x14c/0x180
[ 236.955765] [<ffffff80080826f0>] el0_svc_naked+0x24/0x28
So the kernel crash since the vmalloc area buffer isn'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 <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/mmc/core/sdio_io.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 406e5f0..cf00805 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -10,6 +10,7 @@
*/
#include <linux/export.h>
+#include <linux/mm.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio.h>
@@ -307,7 +308,7 @@ 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) || is_vmalloc_addr(buf))
return -EINVAL;
/* Do the bulk of the transfer using block mode (if supported). */
--
1.9.1
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