Re: [PATCH v3] Bluetooth: btmrvl: fix slab-out-of-bounds access in btmrvl_sdio

[Marcel Holtmann]

Hi Ricky,

> Kasan reported slab-out-of-bounds access in btmrvl_sdio:
> 
> [   33.055400] ==================================================================
> [   33.062585] BUG: KASAN: slab-out-of-bounds in memcpy+0x24/0x50 at addr ffffffc0d89b4a00
> [   33.070529] Read of size 256 by task btmrvl_main_ser/3576
> [   33.075885] =============================================================================
> [   33.084002] BUG kmalloc-256 (Tainted: G    B         ): kasan: bad access detected
> [   33.091511] -----------------------------------------------------------------------------
> <snip...>
> [   33.413498] Call trace:
> [   33.415928] [<ffffffc00020a440>] dump_backtrace+0x0/0x190
> [   33.421288] [<ffffffc00020a5ec>] show_stack+0x1c/0x28
> [   33.426305] [<ffffffc000b3288c>] dump_stack+0xa0/0xf8
> [   33.431320] [<ffffffc000396130>] print_trailer+0x158/0x16c
> [   33.436765] [<ffffffc0003962cc>] object_err+0x48/0x5c
> [   33.441780] [<ffffffc00039be24>] kasan_report+0x344/0x510
> [   33.447141] [<ffffffc00039afd8>] __asan_loadN+0x20/0x150
> [   33.452413] [<ffffffc00039b60c>] memcpy+0x20/0x50
> [   33.457084] [<ffffffc000595fcc>] swiotlb_tbl_map_single+0x2ec/0x310
> [   33.463305] [<ffffffc000596b54>] map_single+0x24/0x30
> [   33.468320] [<ffffffc0005970c8>] swiotlb_map_sg_attrs+0xec/0x21c
> [   33.474286] [<ffffffc000219d4c>] __swiotlb_map_sg_attrs+0x48/0xec
> [   33.480339] [<ffffffc0008ea610>] msdc_prepare_data.isra.11+0xf0/0x11c
> [   33.486733] [<ffffffc0008ecbd0>] msdc_ops_request+0x74/0xf0
> [   33.492266] [<ffffffc0008c6b38>] __mmc_start_request+0x78/0x8c
> [   33.498057] [<ffffffc0008c6d6c>] mmc_start_request+0x220/0x240
> [   33.503848] [<ffffffc0008c6e04>] mmc_wait_for_req+0x78/0x250
> [   33.509468] [<ffffffc0008d70fc>] mmc_io_rw_extended+0x2ec/0x388
> [   33.515347] [<ffffffc0008d8fc0>] sdio_io_rw_ext_helper+0x160/0x268
> [   33.521483] [<ffffffc0008d93fc>] sdio_writesb+0x40/0x50
> [   33.526677] [<ffffffbffc338b38>] btmrvl_sdio_host_to_card+0x124/0x1bc [btmrvl_sdio]
> [   33.534283] [<ffffffbffc3290a0>] btmrvl_service_main_thread+0x384/0x428 [btmrvl]
> [   33.541626] [<ffffffc0002518e8>] kthread+0x140/0x158
> [   33.546550] Memory state around the buggy address:
> [   33.551305]  ffffffc0d89b4980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   33.558474]  ffffffc0d89b4a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [   33.565643] >ffffffc0d89b4a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc
> [   33.572809]                                                                 ^
> [   33.579889]  ffffffc0d89b4b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   33.587055]  ffffffc0d89b4b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> [   33.594221] ==================================================================
> 
> The cause of this is that btmrvl_sdio_host_to_card can access memory region
> out of its allocated space due to:
> 
>  1. the requested block size is smaller than SDIO_BLOCK_SIZE, and/or
>  2. the allocated memory is not BTSDIO_DMA_ALIGN-aligned.
> 
> This patch fixes the issue by allocating a buffer which is big enough for
> SDIO_BLOCK_SIZE transfer and/or BTSDIO_DMA_ALIGN address relocation.
> 
> CC: Wei-Ning Huang <wnhuang@xxxxxxxxxxxx>
> CC: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> CC: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
> 
> Signed-off-by: Ricky Liang <jcliang@xxxxxxxxxxxx>
> ---
> drivers/bluetooth/btmrvl_sdio.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel