| Subject | Re: [PATCH v2 61/63] powerpc: Split memset() to avoid multi-field overflow | From | Christophe Leroy <> | Date | Wed, 18 Aug 2021 08:42:18 +0200 |
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Le 18/08/2021 à 08:05, Kees Cook a écrit : > In preparation for FORTIFY_SOURCE performing compile-time and run-time > field bounds checking for memset(), avoid intentionally writing across > neighboring fields. > > Instead of writing across a field boundary with memset(), move the call > to just the array, and an explicit zeroing of the prior field. > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Qinglang Miao <miaoqinglang@huawei.com> > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> > Cc: Hulk Robot <hulkci@huawei.com> > Cc: Wang Wensheng <wangwensheng4@huawei.com> > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Kees Cook <keescook@chromium.org> > Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> > Link: https://lore.kernel.org/lkml/87czqsnmw9.fsf@mpe.ellerman.id.au > --- > drivers/macintosh/smu.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c > index 94fb63a7b357..59ce431da7ef 100644 > --- a/drivers/macintosh/smu.c > +++ b/drivers/macintosh/smu.c > @@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd) > cmd->read = cmd->info.devaddr & 0x01; > switch(cmd->info.type) { > case SMU_I2C_TRANSFER_SIMPLE: > - memset(&cmd->info.sublen, 0, 4); > + cmd->info.sublen = 0; > + memset(&cmd->info.subaddr, 0, 3);
subaddr[] is a table, should the & be avoided ? And while at it, why not use sizeof(subaddr) instead of 3 ?
> break; > case SMU_I2C_TRANSFER_COMBINED: > cmd->info.devaddr &= 0xfe; >
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