From: Kees Cook keescook@chromium.org
[ Upstream commit 386f771aad15dd535f2368b4adc9958c0160edd4 ]
Since "data" is u32, &data is a "u32 *" type, which means pointer math will move in u32-sized steps. This was meant to be a byte offset, so cast &data to "char *" to aim the copy into the correct location.
Seen with -Warray-bounds (and found by Coverity):
In file included from ./include/linux/string.h:269, from ./arch/powerpc/include/asm/paca.h:15, from ./arch/powerpc/include/asm/current.h:13, from ./include/linux/mutex.h:14, from ./include/linux/notifier.h:14, from ./include/linux/clk.h:14, from drivers/spi/spi-dw-bt1.c:12: In function 'memcpy', inlined from 'dw_spi_bt1_dirmap_copy_from_map' at drivers/spi/spi-dw-bt1.c:87:3: ./include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset 4 is out of the bounds [0, 4] of object 'data' with type 'u32' {aka 'unsigned int'} [-Warray-bounds] 20 | #define __underlying_memcpy __builtin_memcpy | ^ ./include/linux/fortify-string.h:191:9: note: in expansion of macro '__underlying_memcpy' 191 | return __underlying_memcpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~ drivers/spi/spi-dw-bt1.c: In function 'dw_spi_bt1_dirmap_copy_from_map': drivers/spi/spi-dw-bt1.c:77:6: note: 'data' declared here 77 | u32 data; | ^~~~
Addresses-Coverity: CID 1497771 Out-of-bounds access Fixes: abf00907538e ("spi: dw: Add Baikal-T1 SPI Controller glue driver") Signed-off-by: Kees Cook keescook@chromium.org Reviewed-by: Gustavo A. R. Silva gustavoars@kernel.org Acked-by: Serge Semin fancer.lancer@gmail.com Link: https://lore.kernel.org/r/20210211203714.1929862-1-keescook@chromium.org Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-dw-bt1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-dw-bt1.c b/drivers/spi/spi-dw-bt1.c index c279b7891e3ac..bc9d5eab3c589 100644 --- a/drivers/spi/spi-dw-bt1.c +++ b/drivers/spi/spi-dw-bt1.c @@ -84,7 +84,7 @@ static void dw_spi_bt1_dirmap_copy_from_map(void *to, void __iomem *from, size_t if (shift) { chunk = min_t(size_t, 4 - shift, len); data = readl_relaxed(from - shift); - memcpy(to, &data + shift, chunk); + memcpy(to, (char *)&data + shift, chunk); from += chunk; to += chunk; len -= chunk;