On 04/19/18 13:15, Mauro Carvalho Chehab wrote: > Making the cast right for get_user/put_user is not trivial, as > it needs to ensure that the types are the correct ones. > > Improve it by using macros. > > Tested with vivid with: > $ sudo modprobe vivid no_error_inj=1 > $ v4l2-compliance-32bits -a -s10 >32bits && v4l2-compliance-64bits -a -s10 > 64bits && diff -U0 32bits 64bits > --- 32bits 2018-04-17 11:18:29.141240772 -0300 > +++ 64bits 2018-04-17 11:18:40.635282341 -0300 > @@ -1 +1 @@ > -v4l2-compliance SHA : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 32 bits > +v4l2-compliance SHA : bc71e4a67c6fbc5940062843bc41e7c8679634ce, 64 bits > > Using the latest version of v4l-utils with this patch applied: > https://patchwork.linuxtv.org/patch/48746/ > > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> > --- > drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 40 ++++++++++++++++++--------- > 1 file changed, 27 insertions(+), 13 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > index 8c05dd9660d3..d2f0268427c2 100644 > --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c > @@ -30,6 +30,24 @@ > get_user(__assign_tmp, from) || put_user(__assign_tmp, to); \ > }) > > +#define get_user_cast(__x, __ptr) \ > +({ \ > + get_user(__x, (typeof(*__ptr) __user *)(__ptr)); \ > +}) > + > +#define put_user_force(__x, __ptr) \ > +({ \ > + put_user((typeof(*__x) __force *)(__x), __ptr); \ > +}) > + > +#define assign_in_user_cast(to, from) \ > +({ \ > + typeof(*from) __assign_tmp; \ > + \ > + get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\ > +}) Please add comments for these macros. It's not trivially obvious what they do and why they are needed. > + > + > static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > { > long ret = -ENOIOCTLCMD; > @@ -543,8 +561,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64, > return -EFAULT; > > uplane = aux_buf; > - if (put_user((__force struct v4l2_plane *)uplane, > - &p64->m.planes)) > + if (put_user_force(uplane, &p64->m.planes)) > return -EFAULT; > > while (num_planes--) { > @@ -682,7 +699,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64, > > if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || > get_user(tmp, &p32->base) || > - put_user((void __force *)compat_ptr(tmp), &p64->base) || > + put_user_force(compat_ptr(tmp), &p64->base) || > assign_in_user(&p64->capability, &p32->capability) || > assign_in_user(&p64->flags, &p32->flags) || > copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt))) > @@ -831,8 +848,7 @@ static int get_v4l2_ext_controls32(struct file *file, > if (aux_space < count * sizeof(*kcontrols)) > return -EFAULT; > kcontrols = aux_buf; > - if (put_user((__force struct v4l2_ext_control *)kcontrols, > - &p64->controls)) > + if (put_user_force(kcontrols, &p64->controls)) > return -EFAULT; > > for (n = 0; n < count; n++) { > @@ -898,12 +914,11 @@ static int put_v4l2_ext_controls32(struct file *file, > unsigned int size = sizeof(*ucontrols); > u32 id; > > - if (get_user(id, (unsigned int __user *)&kcontrols->id) || > + if (get_user_cast(id, &kcontrols->id) || > put_user(id, &ucontrols->id) || > - assign_in_user(&ucontrols->size, > - (unsigned int __user *)&kcontrols->size) || > + assign_in_user_cast(&ucontrols->size, &kcontrols->size) || > copy_in_user(&ucontrols->reserved2, > - (unsigned int __user *)&kcontrols->reserved2, > + (void __user *)&kcontrols->reserved2, I would prefer to see this change merged with patch 4/6 instead. There is no reason to correct it here. > sizeof(ucontrols->reserved2))) > return -EFAULT; > > @@ -916,7 +931,7 @@ static int put_v4l2_ext_controls32(struct file *file, > size -= sizeof(ucontrols->value64); > > if (copy_in_user(ucontrols, > - (unsigned int __user *)kcontrols, size)) > + (void __user *)kcontrols, size)) Ditto for this one. > return -EFAULT; > > ucontrols++; > @@ -970,10 +985,9 @@ static int get_v4l2_edid32(struct v4l2_edid __user *p64, > if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || > assign_in_user(&p64->pad, &p32->pad) || > assign_in_user(&p64->start_block, &p32->start_block) || > - assign_in_user(&p64->blocks, > - (unsigned char __user *)&p32->blocks) || > + assign_in_user_cast(&p64->blocks, &p32->blocks) || > get_user(tmp, &p32->edid) || > - put_user((void __force *)compat_ptr(tmp), &p64->edid) || > + put_user_force(compat_ptr(tmp), &p64->edid) || > copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved))) > return -EFAULT; > return 0; > Regards, Hans
