The dev_type validation can allow values whose derived event group has no matching physical channel pair. d40_allocate_channel() then indexes phy_res with j + event_group * 2, and __d40_set_prio_rt() uses the same group to select priority and realtime registers.
Reject dev_type values outside the hardware event-group range, and stop the physical-channel search before a partial final channel group can index past phy_res. Reported-by: [email protected] Closes: https://lore.kernel.org/dmaengine/[email protected]/ Assisted-by: Codex:gpt-5-5 Signed-off-by: Linus Walleij <[email protected]> --- drivers/dma/ste_dma40.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index 7c777e410c10..e0c694a1fc8b 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -1739,6 +1739,10 @@ static int d40_validate_conf(struct d40_chan *d40c, bool is_log = conf->mode == STEDMA40_MODE_LOGICAL; bool invalid_dev_type = conf->dev_type < 0; + if (!invalid_dev_type && + D40_TYPE_TO_GROUP(conf->dev_type) >= D40_GROUP_SIZE / 2) + invalid_dev_type = true; + if (!conf->dir) { chan_err(d40c, "Invalid direction.\n"); res = -EINVAL; @@ -1921,8 +1925,12 @@ static int d40_allocate_channel(struct d40_chan *d40c, bool *first_phy_user) } } } else - for (j = 0; j < d40c->base->num_phy_chans; j += 8) { + for (j = 0; j < d40c->base->num_phy_chans; + j += D40_GROUP_SIZE) { int phy_num = j + event_group * 2; + if (phy_num + 1 >= num_phy_chans) + break; + for (i = phy_num; i < phy_num + 2; i++) { if (d40_alloc_mask_set(&phys[i], is_src, @@ -1942,8 +1950,10 @@ static int d40_allocate_channel(struct d40_chan *d40c, bool *first_phy_user) return -EINVAL; /* Find logical channel */ - for (j = 0; j < d40c->base->num_phy_chans; j += 8) { + for (j = 0; j < d40c->base->num_phy_chans; j += D40_GROUP_SIZE) { int phy_num = j + event_group * 2; + if (phy_num + 1 >= num_phy_chans) + break; if (d40c->dma_cfg.use_fixed_channel) { i = d40c->dma_cfg.phy_channel; -- 2.55.0
