On Mon, 15 Apr 2019 21:35:17 +0200, Gustavo A. R. Silva wrote: > > Hi all, > > Friendly ping: > > Who can take this? All platforms that support ISA boards are so old and they don't suffer from Spectre at all. thanks, Takashi > > Thanks > -- > Gustavo > > On 3/26/19 1:32 PM, Gustavo A. R. Silva wrote: > > header->number and i are indirectly controlled by user-space, hence leading > > to a potential exploitation of the Spectre variant 1 vulnerability. > > > > This issue was detected with the help of Smatch: > > > > sound/isa/wavefront/wavefront_synth.c:792 wavefront_send_patch() warn: potential spectre issue 'dev->patch_status' [w] (local cap) > > sound/isa/wavefront/wavefront_synth.c:819 wavefront_send_program() warn: potential spectre issue 'dev->prog_status' [w] (local cap) > > sound/isa/wavefront/wavefront_synth.c:1197 wavefront_send_alias() warn: potential spectre issue 'dev->sample_status' [w] > > sound/isa/wavefront/wavefront_synth.c:1248 wavefront_send_multisample() warn: potential spectre issue 'dev->sample_status' [w] > > sound/isa/wavefront/wavefront_synth.c:1548 wavefront_synth_control() warn: potential spectre issue 'dev->sample_status' [r] (local cap) > > > > Fix this by sanitizing header->number and i before using them to index > > dev->patch_status, dev->prog_status, dev->sample_status. > > > > Notice that given that speculation windows are large, the policy is > > to kill the speculation on the first load and not worry if it can be > > completed with a dependent load/store [1]. > > > > [1] https://lore.kernel.org/lkml/20180423164740.GY17484@xxxxxxxxxxxxxx/ > > > > Cc: stable@xxxxxxxxxxxxxxx > > Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> > > --- > > sound/isa/wavefront/wavefront_synth.c | 17 +++++++++++++++++ > > 1 file changed, 17 insertions(+) > > > > diff --git a/sound/isa/wavefront/wavefront_synth.c b/sound/isa/wavefront/wavefront_synth.c > > index 0b1e4b34b299..a78e125dfdf9 100644 > > --- a/sound/isa/wavefront/wavefront_synth.c > > +++ b/sound/isa/wavefront/wavefront_synth.c > > @@ -31,6 +31,7 @@ > > #include <linux/moduleparam.h> > > #include <linux/slab.h> > > #include <linux/module.h> > > +#include <linux/nospec.h> > > #include <sound/core.h> > > #include <sound/snd_wavefront.h> > > #include <sound/initval.h> > > @@ -788,6 +789,8 @@ wavefront_send_patch (snd_wavefront_t *dev, wavefront_patch_info *header) > > > > if (header->number >= ARRAY_SIZE(dev->patch_status)) > > return -EINVAL; > > + header->number = array_index_nospec(header->number, > > + ARRAY_SIZE(dev->patch_status)); > > > > dev->patch_status[header->number] |= WF_SLOT_FILLED; > > > > @@ -815,6 +818,8 @@ wavefront_send_program (snd_wavefront_t *dev, wavefront_patch_info *header) > > > > if (header->number >= ARRAY_SIZE(dev->prog_status)) > > return -EINVAL; > > + header->number = array_index_nospec(header->number, > > + ARRAY_SIZE(dev->prog_status)); > > > > dev->prog_status[header->number] = WF_SLOT_USED; > > > > @@ -1194,6 +1199,11 @@ wavefront_send_alias (snd_wavefront_t *dev, wavefront_patch_info *header) > > return -EIO; > > } > > > > + if (header->number >= ARRAY_SIZE(dev->sample_status)) > > + return -EINVAL; > > + header->number = array_index_nospec(header->number, > > + ARRAY_SIZE(dev->sample_status)); > > + > > dev->sample_status[header->number] = (WF_SLOT_FILLED|WF_ST_ALIAS); > > > > return (0); > > @@ -1245,6 +1255,12 @@ wavefront_send_multisample (snd_wavefront_t *dev, wavefront_patch_info *header) > > return -EIO; > > } > > > > + if (header->number >= ARRAY_SIZE(dev->sample_status)) { > > + kfree(msample_hdr); > > + return -EINVAL; > > + } > > + header->number = array_index_nospec(header->number, > > + ARRAY_SIZE(dev->sample_status)); > > dev->sample_status[header->number] = (WF_SLOT_FILLED|WF_ST_MULTISAMPLE); > > > > kfree(msample_hdr); > > @@ -1545,6 +1561,7 @@ wavefront_synth_control (snd_wavefront_card_t *acard, > > wc->status = EINVAL; > > return -EINVAL; > > } > > + i = array_index_nospec(i, WF_MAX_SAMPLE); > > wc->rbuf[0] = dev->sample_status[i]; > > wc->status = 0; > > return 0; > > > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
