[ Upstream commit f5912cc19a ]
Using MKWORD() on a byte-sized variable results in OOB read. Expand the
size of the reserved area so both MKWORD and MKBYTE continue to work
without overflow. Silences this warning on a -Warray-bounds build:
drivers/char/mwave/3780i.h:346:22: error: array subscript 'short unsigned int[0]' is partly outside array bounds of 'DSP_ISA_SLAVE_CONTROL[1]' [-Werror=array-bounds]
346 | #define MKWORD(var) (*((unsigned short *)(&var)))
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/char/mwave/3780i.h:356:40: note: in definition of macro 'OutWordDsp'
356 | #define OutWordDsp(index,value) outw(value,usDspBaseIO+index)
| ^~~~~
drivers/char/mwave/3780i.c:373:41: note: in expansion of macro 'MKWORD'
373 | OutWordDsp(DSP_IsaSlaveControl, MKWORD(rSlaveControl));
| ^~~~~~
drivers/char/mwave/3780i.c:358:31: note: while referencing 'rSlaveControl'
358 | DSP_ISA_SLAVE_CONTROL rSlaveControl;
| ^~~~~~~~~~~~~
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211203084206.3104326-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
695ca3e0e2