| Message ID | 20210818060533.3569517-48-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | Introduce strict memcpy() bounds checking | expand |
Kees Cook <keescook@chromium.org> writes: > In preparation for FORTIFY_SOURCE performing compile-time and run-time > field bounds checking for memset(), avoid intentionally writing across > neighboring fields. > > Use memset_startat() so memset() doesn't get confused about writing > beyond the destination member that is intended to be the starting point > of zeroing through the end of the struct. > > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> > --- > drivers/hwtracing/intel_th/msu.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c > index 432ade0842f6..70a07b4e9967 100644 > --- a/drivers/hwtracing/intel_th/msu.c > +++ b/drivers/hwtracing/intel_th/msu.c > @@ -658,13 +658,11 @@ static void msc_buffer_clear_hw_header(struct msc *msc) > > list_for_each_entry(win, &msc->win_list, entry) { > unsigned int blk; > - size_t hw_sz = sizeof(struct msc_block_desc) - > - offsetof(struct msc_block_desc, hw_tag); > > for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { > struct msc_block_desc *bdesc = sg_virt(sg); > > - memset(&bdesc->hw_tag, 0, hw_sz); > + memset_startat(bdesc, 0, hw_tag); > } > } > } > -- > 2.30.2
diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index 432ade0842f6..70a07b4e9967 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -658,13 +658,11 @@ static void msc_buffer_clear_hw_header(struct msc *msc) list_for_each_entry(win, &msc->win_list, entry) { unsigned int blk; - size_t hw_sz = sizeof(struct msc_block_desc) - - offsetof(struct msc_block_desc, hw_tag); for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { struct msc_block_desc *bdesc = sg_virt(sg); - memset(&bdesc->hw_tag, 0, hw_sz); + memset_startat(bdesc, 0, hw_tag); } } }
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Use memset_startat() so memset() doesn't get confused about writing beyond the destination member that is intended to be the starting point of zeroing through the end of the struct. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/hwtracing/intel_th/msu.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)