On 2021/11/19 8:39, Kees Cook wrote: > On Fri, Nov 19, 2021 at 08:17:14AM +0900, Damien Le Moal wrote: >> On 2021/11/19 3:38, Kees Cook wrote: >>> In preparation for FORTIFY_SOURCE performing compile-time and run-time >>> field bounds checking for memcpy(), memmove(), and memset(), avoid >>> intentionally writing across neighboring fields. >>> >>> Use struct_group() in struct command_desc around members acmd and fill, >>> so they can be referenced together. This will allow memset(), memcpy(), >>> and sizeof() to more easily reason about sizes, improve readability, >>> and avoid future warnings about writing beyond the end of acmd: >>> >>> In function 'fortify_memset_chk', >>> inlined from 'sata_fsl_qc_prep' at drivers/ata/sata_fsl.c:534:3: >>> ./include/linux/fortify-string.h:199:4: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning] >>> 199 | __write_overflow_field(); >>> | ^~~~~~~~~~~~~~~~~~~~~~~~ >>> >>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> >> >> This lacks some context with regard to FORTIFY_SOURCE and struct_group(). Is >> that already in 5.16 ? It sounds like it is not. Do you want a ack ? Or do you >> want me to queue this up for 5.17 ? > > Ah yes, some details are here in the earlier "big" series cover letter > here: > https://lore.kernel.org/linux-hardening/20210818060533.3569517-1-keescook@xxxxxxxxxxxx/ > > One of the requests from earlier review was to split it up for separate > trees for the maintainers that wanted to take stuff via their trees > directly. > > The new helpers are landed as of v5.16-rc1, so it can go either way, but > given that the merge window is closed, I would expect this to be for > v5.17. > > I am happy to to carry it in my fortify topic branch that I'm expecting > to send for 5.17, but totally up to you. Some folks like to take these > changes via their trees, others would rather not be bothered with it. :) OK. Since it looks like the compilation warning will trigger only when your big series land in 5.17, I will queue this in for-5.17 (still need to create than one). Is it ok with you ? > > Thanks! > > -Kees > >> >> Cheers. >> >>> --- >>> drivers/ata/sata_fsl.c | 10 ++++++---- >>> 1 file changed, 6 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c >>> index e5838b23c9e0..fec3c9032606 100644 >>> --- a/drivers/ata/sata_fsl.c >>> +++ b/drivers/ata/sata_fsl.c >>> @@ -246,8 +246,10 @@ enum { >>> struct command_desc { >>> u8 cfis[8 * 4]; >>> u8 sfis[8 * 4]; >>> - u8 acmd[4 * 4]; >>> - u8 fill[4 * 4]; >>> + struct_group(cdb, >>> + u8 acmd[4 * 4]; >>> + u8 fill[4 * 4]; >>> + ); >>> u32 prdt[SATA_FSL_MAX_PRD_DIRECT * 4]; >>> u32 prdt_indirect[(SATA_FSL_MAX_PRD - SATA_FSL_MAX_PRD_DIRECT) * 4]; >>> }; >>> @@ -531,8 +533,8 @@ static enum ata_completion_errors sata_fsl_qc_prep(struct ata_queued_cmd *qc) >>> /* setup "ACMD - atapi command" in cmd. desc. if this is ATAPI cmd */ >>> if (ata_is_atapi(qc->tf.protocol)) { >>> desc_info |= ATAPI_CMD; >>> - memset((void *)&cd->acmd, 0, 32); >>> - memcpy((void *)&cd->acmd, qc->cdb, qc->dev->cdb_len); >>> + memset(&cd->cdb, 0, sizeof(cd->cdb)); >>> + memcpy(&cd->cdb, qc->cdb, qc->dev->cdb_len); >>> } >>> >>> if (qc->flags & ATA_QCFLAG_DMAMAP) >>> >> >> >> -- >> Damien Le Moal >> Western Digital Research > -- Damien Le Moal Western Digital Research
