| Message ID | 20210808125012.4715-3-len.baker@gmx.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | drivers/soc: Remove all strcpy() uses | expand |
Hi all! On 08/08/2021 14:50, 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. So, use memcpy() as a safe replacement. > > This is a previous step in the path to remove the strcpy() function > entirely from the kernel. > > Signed-off-by: Len Baker <len.baker@gmx.com> > --- > drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- > drivers/soc/renesas/rcar-sysc.c | 6 ++++-- > 2 files changed, 8 insertions(+), 4 deletions(-) > > 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); Zeroing the allocated bytes is not needed since it's completly overwritten with the strcpy()/memcpy(). > 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; And similar for the second hunk. MfG, Bernd
Hi, Le 08/08/2021 à 17:35, Bernd Petrovitsch a écrit : > Hi all! > > On 08/08/2021 14:50, 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. So, use memcpy() as a safe replacement. >> >> This is a previous step in the path to remove the strcpy() function >> entirely from the kernel. >> >> Signed-off-by: Len Baker <len.baker@gmx.com> >> --- >> drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- >> drivers/soc/renesas/rcar-sysc.c | 6 ++++-- >> 2 files changed, 8 insertions(+), 4 deletions(-) >> >> 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); > Zeroing the allocated bytes is not needed since it's completly > overwritten with the strcpy()/memcpy(). The strcpy()/memcpy() only overwrites the pd->name field, not the whole pd structure. I think that it is needed to keep the kzalloc. Just my 2c, CJ >> 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; > > And similar for the second hunk. > > MfG, > Bernd >
Hi, On Sun, Aug 08, 2021 at 07:06:30PM +0200, Christophe JAILLET wrote: > Hi, > > Le 08/08/2021 à 17:35, Bernd Petrovitsch a écrit : > > Hi all! > > > > On 08/08/2021 14:50, 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. So, use memcpy() as a safe replacement. > > > > > > This is a previous step in the path to remove the strcpy() function > > > entirely from the kernel. > > > > > > Signed-off-by: Len Baker <len.baker@gmx.com> > > > --- > > > drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- > > > drivers/soc/renesas/rcar-sysc.c | 6 ++++-- > > > 2 files changed, 8 insertions(+), 4 deletions(-) > > > > > > 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); > > Zeroing the allocated bytes is not needed since it's completly > > overwritten with the strcpy()/memcpy(). > > The strcpy()/memcpy() only overwrites the pd->name field, not the whole pd > structure. You are right. > I think that it is needed to keep the kzalloc. Yes, I think so. The kzalloc is needed to guarantee that the whole struct is initialize (all the members are initialized with zeros). Regards, Len > > Just my 2c, > CJ > > > > 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; > > > > And similar for the second hunk. > > > > MfG, > > Bernd > > >
On Sun, Aug 8, 2021 at 4:50 PM Len Baker <len.baker@gmx.com> 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. So, use memcpy() as a safe replacement. > > This is a previous step in the path to remove the strcpy() function > entirely from the kernel. > > Signed-off-by: Len Baker <len.baker@gmx.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> i.e. will queue in renesas-devel for v5.15. Gr{oetje,eeting}s, Geert
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;
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. So, use memcpy() as a safe replacement. This is a previous step in the path to remove the strcpy() function entirely from the kernel. Signed-off-by: Len Baker <len.baker@gmx.com> --- drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++-- drivers/soc/renesas/rcar-sysc.c | 6 ++++-- 2 files changed, 8 insertions(+), 4 deletions(-) -- 2.25.1