| Message ID | 20210211203714.1929862-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 386f771aad15dd535f2368b4adc9958c0160edd4 |
| Headers | show |
| Series | spi: dw: Avoid stack content exposure | expand |
On Thu, Feb 11, 2021 at 12:37:14PM -0800, Kees Cook wrote: > 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; > | ^~~~ Can't believe I missed that. Thanks! Acked-by: Serge Semin <fancer.lancer@gmail.com> > > 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> > --- > 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 4aa8596fb1f2..5be6b7b80c21 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; > -- > 2.25.1 >
On Thu, 11 Feb 2021 12:37:14 -0800, Kees Cook wrote: > 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; > | ^~~~ Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next Thanks! [1/1] spi: dw: Avoid stack content exposure commit: 386f771aad15dd535f2368b4adc9958c0160edd4 All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/drivers/spi/spi-dw-bt1.c b/drivers/spi/spi-dw-bt1.c index 4aa8596fb1f2..5be6b7b80c21 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;
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> --- drivers/spi/spi-dw-bt1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)