| Message ID | 20210801131958.6144-1-len.baker@gmx.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | [v3] drivers/soc: Remove all strcpy() uses | expand |
On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote: > strcpy() performs no bounds checking on the destination buffer. This > could result in linear overflows beyond the end of the buffer, leading > to all kinds of misbehaviors. The safe replacement is strscpy(). > While this is true, are any of these uses of strcpy affected by its shortcomings? > Moreover, when the size of the destination buffer cannot be obtained > using "sizeof", use the memcpy function instead of strscpy. > This is not why you're using memcpy, you're using it because you _know_ how many bytes should be copied - because you just did a strlen() and allocated that amount of space. > Signed-off-by: Len Baker <len.baker@gmx.com> > --- > This is a task of the KSPP [1] > > [1] https://github.com/KSPP/linux/issues/88 > > Changelog v1 -> v2 > - Change the "area_name_size" variable for a shorter name (Geert > Uytterhoeven). > - Add the "Reviewed-by: Geert Uytterhoeven" tag. > - Use the memcpy function instead of strscpy function when the > size of the destination buffer cannot be obtained with "sizeof" > (David Laight, Robin Murphy). > > Changelog v2 -> v3 > - Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code > has changed after the v1 review (use of memcpy instead of > strscpy). > > drivers/soc/qcom/pdr_interface.c | 13 +++++++------ > drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- > drivers/soc/renesas/rcar-sysc.c | 6 ++++-- > drivers/soc/ti/knav_dma.c | 2 +- > 4 files changed, 16 insertions(+), 11 deletions(-) > > diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c > index 915d5bc3d46e..cf119fde749d 100644 > --- a/drivers/soc/qcom/pdr_interface.c > +++ b/drivers/soc/qcom/pdr_interface.c > @@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr, > return ret; > > req.enable = enable; > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); > > ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, > &txn, SERVREG_REGISTER_LISTENER_REQ, > @@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds, > return ret; > > req.transaction_id = tid; > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); > > ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, > &txn, SERVREG_SET_ACK_REQ, > @@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds) > return -ENOMEM; > > /* Prepare req message */ > - strcpy(req.service_name, pds->service_name); > + strscpy(req.service_name, pds->service_name, sizeof(req.service_name)); > req.domain_offset_valid = true; > req.domain_offset = 0; > > @@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr, > return ERR_PTR(-ENOMEM); > > pds->service = SERVREG_NOTIFIER_SERVICE; > - strcpy(pds->service_name, service_name); > - strcpy(pds->service_path, service_path); > + strscpy(pds->service_name, service_name, sizeof(pds->service_name)); > + strscpy(pds->service_path, service_path, sizeof(pds->service_path)); > pds->need_locator_lookup = true; > > mutex_lock(&pdr->list_lock); > @@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds) > break; > > /* Prepare req message */ > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, > + sizeof(req.service_path)); There's no need to break this line. Thanks, Bjorn > addr = pds->addr; > break; > } > diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c > index d464ffa1be33..7410b9fa9846 100644 > --- a/drivers/soc/renesas/r8a779a0-sysc.c > +++ b/drivers/soc/renesas/r8a779a0-sysc.c > @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void) > for (i = 0; i < info->num_areas; i++) { > const struct r8a779a0_sysc_area *area = &info->areas[i]; > struct r8a779a0_sysc_pd *pd; > + size_t n; > > if (!area->name) { > /* Skip NULLified area */ > continue; > } > > - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); > + n = strlen(area->name) + 1; > + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); > if (!pd) { > error = -ENOMEM; > goto out_put; > } > > - strcpy(pd->name, area->name); > + memcpy(pd->name, area->name, n); > pd->genpd.name = pd->name; > pd->pdr = area->pdr; > pd->flags = area->flags; > diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c > index 53387a72ca00..b0a80de34c98 100644 > --- a/drivers/soc/renesas/rcar-sysc.c > +++ b/drivers/soc/renesas/rcar-sysc.c > @@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void) > for (i = 0; i < info->num_areas; i++) { > const struct rcar_sysc_area *area = &info->areas[i]; > struct rcar_sysc_pd *pd; > + size_t n; > > if (!area->name) { > /* Skip NULLified area */ > continue; > } > > - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); > + n = strlen(area->name) + 1; > + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); > if (!pd) { > error = -ENOMEM; > goto out_put; > } > > - strcpy(pd->name, area->name); > + memcpy(pd->name, area->name, n); > pd->genpd.name = pd->name; > pd->ch.chan_offs = area->chan_offs; > pd->ch.chan_bit = area->chan_bit; > diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c > index 591d14ebcb11..5f9816d317a5 100644 > --- a/drivers/soc/ti/knav_dma.c > +++ b/drivers/soc/ti/knav_dma.c > @@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node) > dma->max_rx_flow = max_rx_flow; > dma->max_tx_chan = min(max_tx_chan, max_tx_sched); > atomic_set(&dma->ref_count, 0); > - strcpy(dma->name, node->name); > + strscpy(dma->name, node->name, sizeof(dma->name)); > spin_lock_init(&dma->lock); > > for (i = 0; i < dma->max_tx_chan; i++) { > -- > 2.25.1 >
On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote: > strcpy() performs no bounds checking on the destination buffer. This > could result in linear overflows beyond the end of the buffer, leading > to all kinds of misbehaviors. The safe replacement is strscpy(). > > Moreover, when the size of the destination buffer cannot be obtained > using "sizeof", use the memcpy function instead of strscpy. > > Signed-off-by: Len Baker <len.baker@gmx.com> Forgot one thing, it's unclear who should pick this patch up and there's definitely a chance that it will cause merge conflicts regardless of whom of us end up picking it. Could you please split it so that the qcom, renesas and ti pieces can be picked up by respective maintainer? Thanks, Bjorn > --- > This is a task of the KSPP [1] > > [1] https://github.com/KSPP/linux/issues/88 > > Changelog v1 -> v2 > - Change the "area_name_size" variable for a shorter name (Geert > Uytterhoeven). > - Add the "Reviewed-by: Geert Uytterhoeven" tag. > - Use the memcpy function instead of strscpy function when the > size of the destination buffer cannot be obtained with "sizeof" > (David Laight, Robin Murphy). > > Changelog v2 -> v3 > - Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code > has changed after the v1 review (use of memcpy instead of > strscpy). > > drivers/soc/qcom/pdr_interface.c | 13 +++++++------ > drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- > drivers/soc/renesas/rcar-sysc.c | 6 ++++-- > drivers/soc/ti/knav_dma.c | 2 +- > 4 files changed, 16 insertions(+), 11 deletions(-) > > diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c > index 915d5bc3d46e..cf119fde749d 100644 > --- a/drivers/soc/qcom/pdr_interface.c > +++ b/drivers/soc/qcom/pdr_interface.c > @@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr, > return ret; > > req.enable = enable; > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); > > ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, > &txn, SERVREG_REGISTER_LISTENER_REQ, > @@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds, > return ret; > > req.transaction_id = tid; > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); > > ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, > &txn, SERVREG_SET_ACK_REQ, > @@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds) > return -ENOMEM; > > /* Prepare req message */ > - strcpy(req.service_name, pds->service_name); > + strscpy(req.service_name, pds->service_name, sizeof(req.service_name)); > req.domain_offset_valid = true; > req.domain_offset = 0; > > @@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr, > return ERR_PTR(-ENOMEM); > > pds->service = SERVREG_NOTIFIER_SERVICE; > - strcpy(pds->service_name, service_name); > - strcpy(pds->service_path, service_path); > + strscpy(pds->service_name, service_name, sizeof(pds->service_name)); > + strscpy(pds->service_path, service_path, sizeof(pds->service_path)); > pds->need_locator_lookup = true; > > mutex_lock(&pdr->list_lock); > @@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds) > break; > > /* Prepare req message */ > - strcpy(req.service_path, pds->service_path); > + strscpy(req.service_path, pds->service_path, > + sizeof(req.service_path)); > addr = pds->addr; > break; > } > diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c > index d464ffa1be33..7410b9fa9846 100644 > --- a/drivers/soc/renesas/r8a779a0-sysc.c > +++ b/drivers/soc/renesas/r8a779a0-sysc.c > @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void) > for (i = 0; i < info->num_areas; i++) { > const struct r8a779a0_sysc_area *area = &info->areas[i]; > struct r8a779a0_sysc_pd *pd; > + size_t n; > > if (!area->name) { > /* Skip NULLified area */ > continue; > } > > - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); > + n = strlen(area->name) + 1; > + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); > if (!pd) { > error = -ENOMEM; > goto out_put; > } > > - strcpy(pd->name, area->name); > + memcpy(pd->name, area->name, n); > pd->genpd.name = pd->name; > pd->pdr = area->pdr; > pd->flags = area->flags; > diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c > index 53387a72ca00..b0a80de34c98 100644 > --- a/drivers/soc/renesas/rcar-sysc.c > +++ b/drivers/soc/renesas/rcar-sysc.c > @@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void) > for (i = 0; i < info->num_areas; i++) { > const struct rcar_sysc_area *area = &info->areas[i]; > struct rcar_sysc_pd *pd; > + size_t n; > > if (!area->name) { > /* Skip NULLified area */ > continue; > } > > - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); > + n = strlen(area->name) + 1; > + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); > if (!pd) { > error = -ENOMEM; > goto out_put; > } > > - strcpy(pd->name, area->name); > + memcpy(pd->name, area->name, n); > pd->genpd.name = pd->name; > pd->ch.chan_offs = area->chan_offs; > pd->ch.chan_bit = area->chan_bit; > diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c > index 591d14ebcb11..5f9816d317a5 100644 > --- a/drivers/soc/ti/knav_dma.c > +++ b/drivers/soc/ti/knav_dma.c > @@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node) > dma->max_rx_flow = max_rx_flow; > dma->max_tx_chan = min(max_tx_chan, max_tx_sched); > atomic_set(&dma->ref_count, 0); > - strcpy(dma->name, node->name); > + strscpy(dma->name, node->name, sizeof(dma->name)); > spin_lock_init(&dma->lock); > > for (i = 0; i < dma->max_tx_chan; i++) { > -- > 2.25.1 >
Hi, On Wed, Aug 04, 2021 at 05:23:54PM -0500, Bjorn Andersson wrote: > On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote: > > > strcpy() performs no bounds checking on the destination buffer. This > > could result in linear overflows beyond the end of the buffer, leading > > to all kinds of misbehaviors. The safe replacement is strscpy(). > > > > While this is true, are any of these uses of strcpy affected by its > shortcomings? No, this patch is only an effort to clean up the proliferation of str*() functions in the kernel. > > Moreover, when the size of the destination buffer cannot be obtained > > using "sizeof", use the memcpy function instead of strscpy. > > > > This is not why you're using memcpy, you're using it because you _know_ > how many bytes should be copied - because you just did a strlen() and > allocated that amount of space. Understood, I will change the commit message. > > > [...] > > /* Prepare req message */ > > - strcpy(req.service_path, pds->service_path); > > + strscpy(req.service_path, pds->service_path, > > + sizeof(req.service_path)); > > There's no need to break this line. Ok, thanks. Regards, Len
diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c index 915d5bc3d46e..cf119fde749d 100644 --- a/drivers/soc/qcom/pdr_interface.c +++ b/drivers/soc/qcom/pdr_interface.c @@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr, return ret; req.enable = enable; - strcpy(req.service_path, pds->service_path); + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, &txn, SERVREG_REGISTER_LISTENER_REQ, @@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds, return ret; req.transaction_id = tid; - strcpy(req.service_path, pds->service_path); + strscpy(req.service_path, pds->service_path, sizeof(req.service_path)); ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr, &txn, SERVREG_SET_ACK_REQ, @@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds) return -ENOMEM; /* Prepare req message */ - strcpy(req.service_name, pds->service_name); + strscpy(req.service_name, pds->service_name, sizeof(req.service_name)); req.domain_offset_valid = true; req.domain_offset = 0; @@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr, return ERR_PTR(-ENOMEM); pds->service = SERVREG_NOTIFIER_SERVICE; - strcpy(pds->service_name, service_name); - strcpy(pds->service_path, service_path); + strscpy(pds->service_name, service_name, sizeof(pds->service_name)); + strscpy(pds->service_path, service_path, sizeof(pds->service_path)); pds->need_locator_lookup = true; mutex_lock(&pdr->list_lock); @@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds) break; /* Prepare req message */ - strcpy(req.service_path, pds->service_path); + strscpy(req.service_path, pds->service_path, + sizeof(req.service_path)); addr = pds->addr; break; } diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c index d464ffa1be33..7410b9fa9846 100644 --- a/drivers/soc/renesas/r8a779a0-sysc.c +++ b/drivers/soc/renesas/r8a779a0-sysc.c @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void) for (i = 0; i < info->num_areas; i++) { const struct r8a779a0_sysc_area *area = &info->areas[i]; struct r8a779a0_sysc_pd *pd; + size_t n; if (!area->name) { /* Skip NULLified area */ continue; } - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); + n = strlen(area->name) + 1; + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); if (!pd) { error = -ENOMEM; goto out_put; } - strcpy(pd->name, area->name); + memcpy(pd->name, area->name, n); pd->genpd.name = pd->name; pd->pdr = area->pdr; pd->flags = area->flags; diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c index 53387a72ca00..b0a80de34c98 100644 --- a/drivers/soc/renesas/rcar-sysc.c +++ b/drivers/soc/renesas/rcar-sysc.c @@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void) for (i = 0; i < info->num_areas; i++) { const struct rcar_sysc_area *area = &info->areas[i]; struct rcar_sysc_pd *pd; + size_t n; if (!area->name) { /* Skip NULLified area */ continue; } - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); + n = strlen(area->name) + 1; + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); if (!pd) { error = -ENOMEM; goto out_put; } - strcpy(pd->name, area->name); + memcpy(pd->name, area->name, n); pd->genpd.name = pd->name; pd->ch.chan_offs = area->chan_offs; pd->ch.chan_bit = area->chan_bit; diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c index 591d14ebcb11..5f9816d317a5 100644 --- a/drivers/soc/ti/knav_dma.c +++ b/drivers/soc/ti/knav_dma.c @@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node) dma->max_rx_flow = max_rx_flow; dma->max_tx_chan = min(max_tx_chan, max_tx_sched); atomic_set(&dma->ref_count, 0); - strcpy(dma->name, node->name); + strscpy(dma->name, node->name, sizeof(dma->name)); spin_lock_init(&dma->lock); for (i = 0; i < dma->max_tx_chan; i++) {
strcpy() performs no bounds checking on the destination buffer. This could result in linear overflows beyond the end of the buffer, leading to all kinds of misbehaviors. The safe replacement is strscpy(). Moreover, when the size of the destination buffer cannot be obtained using "sizeof", use the memcpy function instead of strscpy. Signed-off-by: Len Baker <len.baker@gmx.com> --- This is a task of the KSPP [1] [1] https://github.com/KSPP/linux/issues/88 Changelog v1 -> v2 - Change the "area_name_size" variable for a shorter name (Geert Uytterhoeven). - Add the "Reviewed-by: Geert Uytterhoeven" tag. - Use the memcpy function instead of strscpy function when the size of the destination buffer cannot be obtained with "sizeof" (David Laight, Robin Murphy). Changelog v2 -> v3 - Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code has changed after the v1 review (use of memcpy instead of strscpy). drivers/soc/qcom/pdr_interface.c | 13 +++++++------ drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- drivers/soc/renesas/rcar-sysc.c | 6 ++++-- drivers/soc/ti/knav_dma.c | 2 +- 4 files changed, 16 insertions(+), 11 deletions(-) -- 2.25.1