diff options
| author | Daniel Mentz <danielmentz@google.com> | 2017-07-19 16:03:19 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-12-14 17:26:48 +0100 |
| commit | b70a26cc0275b1ed647ef79c8d0bfa1e109f5bc1 (patch) | |
| tree | 06ec66acd9f78a3d5ade8ea78757a743fe6109c5 | |
| parent | c4fd5633f12890814abace672c71423eb6803e77 (diff) | |
v4l2: Refactor, fix security bug in compat ioctl32
The 32-bit compat v4l2 ioctl is implemented based on its 64-bit
equivalent. It converts 32-bit data structures into its 64-bit
equivalents and needs to provide the data to the 64-bit ioctl in user
space memory which is commonly allocated using
compat_alloc_user_space(). However, due to how that function is
implemented, it can only be called a single time for every syscall
invocation. Supposedly to avoid this limitation, the existing code uses
a mix of memory from the kernel stack and memory allocated through
compat_alloc_user_space(). Under normal circumstances, this would not
work, because the 64-bit ioctl expects all pointers to point to user
space memory. As a workaround, set_fs(KERNEL_DS) is called to
temporarily disable this extra safety check and allow kernel pointers.
However, this might introduce a security vulnerability: The
result of the 32-bit to 64-bit conversion is writeable by user space
because the output buffer has been allocated via
compat_alloc_user_space(). A malicious user space process could then
manipulate pointers inside this output buffer, and due to the previous
set_fs(KERNEL_DS) call, functions like get_user() or put_user() no longer
prevent kernel memory access.
The new approach is to pre-calculate the total amount of user space
memory that is needed, allocate it using compat_alloc_user_space() and
then divide up the allocated memory to accommodate all data structures
that need to be converted.
An alternative approach would have been to retain the union type karg
that they allocated on the kernel stack in do_video_ioctl(), copy all
data from user space into karg and then back to user space. However,
we decided against this approach because it does not align with other
compat syscall implementations. Instead, we tried to replicate the
get_user/put_user pairs as found in other places in the kernel:
if (get_user(clipcount, &up->clipcount) ||
put_user(clipcount, &kp->clipcount)) return -EFAULT;
BUG: 34624167
Change-Id: Ica92695d8ddf60c0a067ea2f833f22a71710932e
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Reported-by: C0RE Team
Signed-off-by: Mister Oyster <oysterized@gmail.com>
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 597 |
1 files changed, 373 insertions, 224 deletions
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index d3a60c31c..78b670e71 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -20,6 +20,13 @@ #include <media/v4l2-dev.h> #include <media/v4l2-ioctl.h> +#define convert_in_user(srcptr, dstptr) \ +({ \ + typeof(*srcptr) val; \ + \ + get_user(val, srcptr) || put_user(val, dstptr); \ +}) + static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { long ret = -ENOIOCTLCMD; @@ -45,27 +52,45 @@ struct v4l2_window32 { compat_caddr_t bitmap; }; -static int get_v4l2_window32(struct v4l2_window *kp, struct v4l2_window32 __user *up) +static int bufsize_v4l2_window32(struct v4l2_window32 __user *up) +{ + __u32 clipcount; + + if (get_user(clipcount, &up->clipcount)) + return -EFAULT; + if (clipcount > 2048) + return -EINVAL; + return clipcount * sizeof(struct v4l2_clip); +} + +static int get_v4l2_window32(struct v4l2_window __user *kp, struct + v4l2_window32 __user *up, void __user *aux_buf, int aux_space) { + __u32 clipcount; + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_window32)) || - copy_from_user(&kp->w, &up->w, sizeof(up->w)) || - get_user(kp->field, &up->field) || - get_user(kp->chromakey, &up->chromakey) || - get_user(kp->clipcount, &up->clipcount)) + copy_in_user(&kp->w, &up->w, sizeof(up->w)) || + convert_in_user(&up->field, &kp->field) || + convert_in_user(&up->chromakey, &kp->chromakey) || + get_user(clipcount, &up->clipcount) || + put_user(clipcount, &kp->clipcount)) return -EFAULT; - if (kp->clipcount > 2048) + if (clipcount > 2048) return -EINVAL; - if (kp->clipcount) { + if (clipcount) { struct v4l2_clip32 __user *uclips; struct v4l2_clip __user *kclips; - int n = kp->clipcount; + int n = clipcount; compat_caddr_t p; if (get_user(p, &up->clips)) return -EFAULT; uclips = compat_ptr(p); - kclips = compat_alloc_user_space(n * sizeof(struct v4l2_clip)); - kp->clips = kclips; + if (aux_space < n * sizeof(struct v4l2_clip)) + return -EFAULT; + kclips = aux_buf; + if (put_user(kclips, &kp->clips)) + return -EFAULT; while (--n >= 0) { if (copy_in_user(&kclips->c, &uclips->c, sizeof(uclips->c))) return -EFAULT; @@ -74,75 +99,77 @@ static int get_v4l2_window32(struct v4l2_window *kp, struct v4l2_window32 __user uclips += 1; kclips += 1; } - } else - kp->clips = NULL; + } else { + if (put_user(NULL, &kp->clips)) + return -EFAULT; + } return 0; } -static int put_v4l2_window32(struct v4l2_window *kp, struct v4l2_window32 __user *up) +static int put_v4l2_window32(struct v4l2_window __user *kp, struct v4l2_window32 __user *up) { - if (copy_to_user(&up->w, &kp->w, sizeof(kp->w)) || - put_user(kp->field, &up->field) || - put_user(kp->chromakey, &up->chromakey) || - put_user(kp->clipcount, &up->clipcount)) - return -EFAULT; + if (copy_in_user(&up->w, &kp->w, sizeof(kp->w)) || + convert_in_user(&kp->field, &up->field) || + convert_in_user(&kp->chromakey, &up->chromakey) || + convert_in_user(&kp->clipcount, &up->clipcount)) + return -EFAULT; return 0; } -static inline int get_v4l2_pix_format(struct v4l2_pix_format *kp, struct v4l2_pix_format __user *up) +static inline int get_v4l2_pix_format(struct v4l2_pix_format __user *kp, struct v4l2_pix_format __user *up) { - if (copy_from_user(kp, up, sizeof(struct v4l2_pix_format))) + if (copy_in_user(kp, up, sizeof(struct v4l2_pix_format))) return -EFAULT; return 0; } -static inline int get_v4l2_pix_format_mplane(struct v4l2_pix_format_mplane *kp, +static inline int get_v4l2_pix_format_mplane(struct v4l2_pix_format_mplane __user *kp, struct v4l2_pix_format_mplane __user *up) { - if (copy_from_user(kp, up, sizeof(struct v4l2_pix_format_mplane))) + if (copy_in_user(kp, up, sizeof(struct v4l2_pix_format_mplane))) return -EFAULT; return 0; } -static inline int put_v4l2_pix_format(struct v4l2_pix_format *kp, struct v4l2_pix_format __user *up) +static inline int put_v4l2_pix_format(struct v4l2_pix_format __user *kp, struct v4l2_pix_format __user *up) { - if (copy_to_user(up, kp, sizeof(struct v4l2_pix_format))) + if (copy_in_user(up, kp, sizeof(struct v4l2_pix_format))) return -EFAULT; return 0; } -static inline int put_v4l2_pix_format_mplane(struct v4l2_pix_format_mplane *kp, +static inline int put_v4l2_pix_format_mplane(struct v4l2_pix_format_mplane __user *kp, struct v4l2_pix_format_mplane __user *up) { - if (copy_to_user(up, kp, sizeof(struct v4l2_pix_format_mplane))) + if (copy_in_user(up, kp, sizeof(struct v4l2_pix_format_mplane))) return -EFAULT; return 0; } -static inline int get_v4l2_vbi_format(struct v4l2_vbi_format *kp, struct v4l2_vbi_format __user *up) +static inline int get_v4l2_vbi_format(struct v4l2_vbi_format __user *kp, struct v4l2_vbi_format __user *up) { - if (copy_from_user(kp, up, sizeof(struct v4l2_vbi_format))) + if (copy_in_user(kp, up, sizeof(struct v4l2_vbi_format))) return -EFAULT; return 0; } -static inline int put_v4l2_vbi_format(struct v4l2_vbi_format *kp, struct v4l2_vbi_format __user *up) +static inline int put_v4l2_vbi_format(struct v4l2_vbi_format __user *kp, struct v4l2_vbi_format __user *up) { - if (copy_to_user(up, kp, sizeof(struct v4l2_vbi_format))) + if (copy_in_user(up, kp, sizeof(struct v4l2_vbi_format))) return -EFAULT; return 0; } -static inline int get_v4l2_sliced_vbi_format(struct v4l2_sliced_vbi_format *kp, struct v4l2_sliced_vbi_format __user *up) +static inline int get_v4l2_sliced_vbi_format(struct v4l2_sliced_vbi_format __user *kp, struct v4l2_sliced_vbi_format __user *up) { - if (copy_from_user(kp, up, sizeof(struct v4l2_sliced_vbi_format))) + if (copy_in_user(kp, up, sizeof(struct v4l2_sliced_vbi_format))) return -EFAULT; return 0; } -static inline int put_v4l2_sliced_vbi_format(struct v4l2_sliced_vbi_format *kp, struct v4l2_sliced_vbi_format __user *up) +static inline int put_v4l2_sliced_vbi_format(struct v4l2_sliced_vbi_format __user *kp, struct v4l2_sliced_vbi_format __user *up) { - if (copy_to_user(up, kp, sizeof(struct v4l2_sliced_vbi_format))) + if (copy_in_user(up, kp, sizeof(struct v4l2_sliced_vbi_format))) return -EFAULT; return 0; } @@ -176,12 +203,31 @@ struct v4l2_create_buffers32 { __u32 reserved[8]; }; -static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +static int __bufsize_v4l2_format32(struct v4l2_format32 __user *up) { - if (get_user(kp->type, &up->type)) + __u32 type; + + if (get_user(type, &up->type)) return -EFAULT; - switch (kp->type) { + switch (type) { + case V4L2_BUF_TYPE_VIDEO_OVERLAY: + case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY: + return bufsize_v4l2_window32(&up->fmt.win); + default: + return 0; + } +} + +static int __get_v4l2_format32(struct v4l2_format __user *kp, struct + v4l2_format32 __user *up, void __user *aux_buf, int aux_space) +{ + __u32 type; + + if (get_user(type, &up->type) || put_user(type, &kp->type)) + return -EFAULT; + + switch (type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_OUTPUT: return get_v4l2_pix_format(&kp->fmt.pix, &up->fmt.pix); @@ -191,7 +237,7 @@ static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us &up->fmt.pix_mp); case V4L2_BUF_TYPE_VIDEO_OVERLAY: case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY: - return get_v4l2_window32(&kp->fmt.win, &up->fmt.win); + return get_v4l2_window32(&kp->fmt.win, &up->fmt.win, aux_buf, aux_space); case V4L2_BUF_TYPE_VBI_CAPTURE: case V4L2_BUF_TYPE_VBI_OUTPUT: return get_v4l2_vbi_format(&kp->fmt.vbi, &up->fmt.vbi); @@ -205,24 +251,46 @@ static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us } } -static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +static int bufsize_v4l2_format32(struct v4l2_format32 __user *up) { if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32))) return -EFAULT; - return __get_v4l2_format32(kp, up); + return __bufsize_v4l2_format32(up); } -static int get_v4l2_create32(struct v4l2_create_buffers *kp, struct v4l2_create_buffers32 __user *up) +static int get_v4l2_format32(struct v4l2_format __user *kp, struct + v4l2_format32 __user *up, void __user *aux_buf, int aux_space) +{ + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32))) + return -EFAULT; + return __get_v4l2_format32(kp, up, aux_buf, aux_space); +} + +static int bufsize_v4l2_create32(struct v4l2_create_buffers32 __user *up) +{ + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_create_buffers32))) + return -EFAULT; + return __bufsize_v4l2_format32(&up->format); +} + +static int get_v4l2_create32(struct v4l2_create_buffers __user *kp, struct + v4l2_create_buffers32 __user *up, void __user *aux_buf, + int aux_space) { if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_create_buffers32)) || - copy_from_user(kp, up, offsetof(struct v4l2_create_buffers32, format))) + copy_in_user(kp, up, offsetof(struct v4l2_create_buffers32, format))) return -EFAULT; - return __get_v4l2_format32(&kp->format, &up->format); + return __get_v4l2_format32(&kp->format, &up->format, aux_buf, aux_space); } -static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +static int __put_v4l2_format32(struct v4l2_format __user *kp, struct v4l2_format32 __user *up) { - switch (kp->type) { + __u32 type; + + if (get_user(type, &kp->type)) + return -EFAULT; + + switch (type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_OUTPUT: return put_v4l2_pix_format(&kp->fmt.pix, &up->fmt.pix); @@ -246,7 +314,7 @@ static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __us } } -static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +static int put_v4l2_format32(struct v4l2_format __user *kp, struct v4l2_format32 __user *up) { if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_format32)) || put_user(kp->type, &up->type)) @@ -254,10 +322,10 @@ static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user return __put_v4l2_format32(kp, up); } -static int put_v4l2_create32(struct v4l2_create_buffers *kp, struct v4l2_create_buffers32 __user *up) +static int put_v4l2_create32(struct v4l2_create_buffers __user *kp, struct v4l2_create_buffers32 __user *up) { if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_create_buffers32)) || - copy_to_user(up, kp, offsetof(struct v4l2_create_buffers32, format.fmt))) + copy_in_user(up, kp, offsetof(struct v4l2_create_buffers32, format.fmt))) return -EFAULT; return __put_v4l2_format32(&kp->format, &up->format); } @@ -271,24 +339,24 @@ struct v4l2_standard32 { __u32 reserved[4]; }; -static int get_v4l2_standard32(struct v4l2_standard *kp, struct v4l2_standard32 __user *up) +static int get_v4l2_standard32(struct v4l2_standard __user *kp, struct v4l2_standard32 __user *up) { /* other fields are not set by the user, nor used by the driver */ if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_standard32)) || - get_user(kp->index, &up->index)) + convert_in_user(&up->index, &kp->index)) return -EFAULT; return 0; } -static int put_v4l2_standard32(struct v4l2_standard *kp, struct v4l2_standard32 __user *up) +static int put_v4l2_standard32(struct v4l2_standard __user *kp, struct v4l2_standard32 __user *up) { if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_standard32)) || - put_user(kp->index, &up->index) || - put_user(kp->id, &up->id) || - copy_to_user(up->name, kp->name, 24) || - copy_to_user(&up->frameperiod, &kp->frameperiod, sizeof(kp->frameperiod)) || - put_user(kp->framelines, &up->framelines) || - copy_to_user(up->reserved, kp->reserved, 4 * sizeof(__u32))) + convert_in_user(&kp->index, &up->index) || + copy_in_user(up->id, &kp->id, sizeof(__u64)) || + copy_in_user(up->name, kp->name, 24) || + copy_in_user(&up->frameperiod, &kp->frameperiod, sizeof(kp->frameperiod)) || + convert_in_user(&kp->framelines, &up->framelines) || + copy_in_user(up->reserved, kp->reserved, 4 * sizeof(__u32))) return -EFAULT; return 0; } @@ -331,7 +399,6 @@ struct v4l2_buffer32 { static int get_v4l2_plane32(struct v4l2_plane *up, struct v4l2_plane32 *up32, enum v4l2_memory memory) { - void __user *up_pln; compat_long_t p; if (copy_in_user(up, up32, 2 * sizeof(__u32)) || @@ -340,10 +407,9 @@ static int get_v4l2_plane32(struct v4l2_plane *up, struct v4l2_plane32 *up32, return -EFAULT; if (memory == V4L2_MEMORY_USERPTR) { - if (get_user(p, &up32->m.userptr)) - return -EFAULT; - up_pln = compat_ptr(p); - if (put_user((unsigned long)up_pln, &up->m.userptr)) + if (get_user(p, &up32->m.userptr) || + put_user((unsigned long) compat_ptr(p), + &up->m.userptr)) return -EFAULT; } else if (memory == V4L2_MEMORY_DMABUF) { if (copy_in_user(&up->m.fd, &up32->m.fd, sizeof(int))) @@ -380,8 +446,34 @@ static int put_v4l2_plane32(struct v4l2_plane *up, struct v4l2_plane32 *up32, return 0; } -static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user *up) +static int bufsize_v4l2_buffer32(struct v4l2_buffer32 __user *up) +{ + __u32 type; + __u32 length; + + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_buffer32)) || + get_user(type, &up->type) || + get_user(length, &up->length)) + return -EFAULT; + + if (V4L2_TYPE_IS_MULTIPLANAR(type)) { + if (length > VIDEO_MAX_PLANES) + return -EINVAL; + + /* We don't really care if userspace decides to kill itself + * by passing a very big length value + */ + return length * sizeof(struct v4l2_plane); + } + return 0; +} + +static int get_v4l2_buffer32(struct v4l2_buffer __user *kp, struct + v4l2_buffer32 __user *up, void __user *aux_buf, int aux_space) { + __u32 type; + __u32 length; + enum v4l2_memory memory; struct v4l2_plane32 __user *uplane32; struct v4l2_plane __user *uplane; compat_caddr_t p; @@ -389,38 +481,40 @@ static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user int ret; if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_buffer32)) || - get_user(kp->index, &up->index) || - get_user(kp->type, &up->type) || - get_user(kp->flags, &up->flags) || - get_user(kp->memory, &up->memory) || - get_user(kp->length, &up->length)) + convert_in_user(&up->index, &kp->index) || + get_user(type, &up->type) || + put_user(type, &kp->type) || + convert_in_user(&up->flags, &kp->flags) || + get_user(memory, &up->memory) || + put_user(memory, &kp->memory) || + convert_in_user(&up->length, &kp->length) || + get_user(length, &up->length) || + put_user(length, &kp->length)) return -EFAULT; - if (V4L2_TYPE_IS_OUTPUT(kp->type)) - if (get_user(kp->bytesused, &up->bytesused) || - get_user(kp->field, &up->field) || - get_user(kp->timestamp.tv_sec, &up->timestamp.tv_sec) || - get_user(kp->timestamp.tv_usec, - &up->timestamp.tv_usec)) + if (V4L2_TYPE_IS_OUTPUT(type)) + if (convert_in_user(&up->bytesused, &kp->bytesused) || + convert_in_user(&up->field, &kp->field) || + convert_in_user(&up->timestamp.tv_sec, &kp->timestamp.tv_sec) || + convert_in_user(&up->timestamp.tv_usec, + &kp->timestamp.tv_usec)) return -EFAULT; - if (V4L2_TYPE_IS_PRIVATE(kp->type)) { + if (V4L2_TYPE_IS_PRIVATE(type)) { compat_long_t tmp; - if (get_user(kp->length, &up->length) || - get_user(tmp, &up->m.userptr)) + if (get_user(tmp, &up->m.userptr) || + put_user((unsigned long) compat_ptr(tmp), + &kp->m.userptr)) return -EFAULT; - - kp->m.userptr = (unsigned long)compat_ptr(tmp); } - if (V4L2_TYPE_IS_MULTIPLANAR(kp->type)) { - num_planes = kp->length; + if (V4L2_TYPE_IS_MULTIPLANAR(type)) { + num_planes = length; if (num_planes == 0) { - kp->m.planes = NULL; /* num_planes == 0 is legal, e.g. when userspace doesn't * need planes array on DQBUF*/ - return 0; + return put_user(NULL, &kp->m.planes); } if (get_user(p, &up->m.planes)) @@ -433,39 +527,44 @@ static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user /* We don't really care if userspace decides to kill itself * by passing a very big num_planes value */ - uplane = compat_alloc_user_space(num_planes * - sizeof(struct v4l2_plane)); - kp->m.planes = uplane; + if (aux_space < num_planes * sizeof(struct v4l2_plane)) + return -EFAULT; + + uplane = aux_buf; + if (put_user((__force struct v4l2_plane *)uplane, + &kp->m.planes)) + return -EFAULT; while (--num_planes >= 0) { - ret = get_v4l2_plane32(uplane, uplane32, kp->memory); + ret = get_v4l2_plane32(uplane, uplane32, memory); if (ret) return ret; ++uplane; ++uplane32; } } else { - switch (kp->memory) { + switch (memory) { case V4L2_MEMORY_MMAP: - if (get_user(kp->m.offset, &up->m.offset)) + if (convert_in_user(&up->m.offset, &kp->m.offset)) return -EFAULT; break; case V4L2_MEMORY_USERPTR: { - compat_long_t tmp; + compat_long_t tmp; - if (get_user(tmp, &up->m.userptr)) - return -EFAULT; - - kp->m.userptr = (unsigned long)compat_ptr(tmp); + if (get_user(tmp, &up->m.userptr) || + put_user((unsigned long) + compat_ptr(tmp), + &kp->m.userptr)) + return -EFAULT; } break; case V4L2_MEMORY_OVERLAY: - if (get_user(kp->m.offset, &up->m.offset)) + if (convert_in_user(&up->m.offset, &kp->m.offset)) return -EFAULT; break; case V4L2_MEMORY_DMABUF: - if (get_user(kp->m.fd, &up->m.fd)) + if (convert_in_user(&up->m.fd, &kp->m.fd)) return -EFAULT; break; } @@ -474,8 +573,11 @@ static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user return 0; } -static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user *up) +static int put_v4l2_buffer32(struct v4l2_buffer __user *kp, struct v4l2_buffer32 __user *up) { + __u32 type; + __u32 length; + enum v4l2_memory memory; struct v4l2_plane32 __user *uplane32; struct v4l2_plane __user *uplane; compat_caddr_t p; @@ -483,62 +585,65 @@ static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user int ret; if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_buffer32)) || - put_user(kp->index, &up->index) || - put_user(kp->type, &up->type) || - put_user(kp->flags, &up->flags) || - put_user(kp->memory, &up->memory)) + convert_in_user(&kp->index, &up->index) || + get_user(type, &kp->type) || + put_user(type, &up->type) || + convert_in_user(&kp->flags, &up->flags) || + get_user(memory, &kp->memory) || + put_user(memory, &up->memory)) return -EFAULT; - if (put_user(kp->bytesused, &up->bytesused) || - put_user(kp->field, &up->field) || - put_user(kp->timestamp.tv_sec, &up->timestamp.tv_sec) || - put_user(kp->timestamp.tv_usec, &up->timestamp.tv_usec) || - copy_to_user(&up->timecode, &kp->timecode, sizeof(struct v4l2_timecode)) || - put_user(kp->sequence, &up->sequence) || - put_user(kp->reserved2, &up->reserved2) || - put_user(kp->reserved, &up->reserved) || - put_user(kp->length, &up->length)) + if (convert_in_user(&kp->bytesused, &up->bytesused) || + convert_in_user(&kp->field, &up->field) || + convert_in_user(&kp->timestamp.tv_sec, &up->timestamp.tv_sec) || + convert_in_user(&kp->timestamp.tv_usec, &up->timestamp.tv_usec) || + copy_in_user(&up->timecode, &kp->timecode, sizeof(struct v4l2_timecode)) || + convert_in_user(&kp->sequence, &up->sequence) || + convert_in_user(&kp->reserved2, &up->reserved2) || + convert_in_user(&kp->reserved, &up->reserved) || + get_user(length, &kp->length) || + put_user(length, &up->length)) return -EFAULT; - if (V4L2_TYPE_IS_PRIVATE(kp->type)) { - if (put_user(kp->length, &up->length) || - put_user(kp->m.userptr, &up->m.userptr)) + if (V4L2_TYPE_IS_PRIVATE(type)) { + if (convert_in_user(&kp->m.userptr, &up->m.userptr)) return -EFAULT; } - if (V4L2_TYPE_IS_MULTIPLANAR(kp->type)) { - num_planes = kp->length; + if (V4L2_TYPE_IS_MULTIPLANAR(type)) { + num_planes = length; if (num_planes == 0) return 0; - uplane = kp->m.planes; + if (get_user(uplane, ((__force struct v4l2_plane __user **)&kp->m.planes))) + return -EFAULT; if (get_user(p, &up->m.planes)) return -EFAULT; uplane32 = compat_ptr(p); while (--num_planes >= 0) { - ret = put_v4l2_plane32(uplane, uplane32, kp->memory); + ret = put_v4l2_plane32(uplane, uplane32, memory); if (ret) return ret; ++uplane; ++uplane32; } } else { - switch (kp->memory) { + switch (memory) { case V4L2_MEMORY_MMAP: - if (put_user(kp->m.offset, &up->m.offset)) + if (convert_in_user(&kp->m.offset, &up->m.offset)) return -EFAULT; break; case V4L2_MEMORY_USERPTR: - if (put_user(kp->m.userptr, &up->m.userptr)) + if (convert_in_user(&kp->m.userptr, &up->m.userptr)) return -EFAULT; break; case V4L2_MEMORY_OVERLAY: - if (put_user(kp->m.offset, &up->m.offset)) + if (convert_in_user(&kp->m.offset, &up->m.offset)) return -EFAULT; break; case V4L2_MEMORY_DMABUF: - if (put_user(kp->m.fd, &up->m.fd)) + if (convert_in_user(&kp->m.fd, &up->m.fd)) return -EFAULT; break; } @@ -554,30 +659,31 @@ struct v4l2_framebuffer32 { struct v4l2_pix_format fmt; }; -static int get_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_framebuffer32 __user *up) +static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp, struct v4l2_framebuffer32 __user *up) { - u32 tmp; + compat_caddr_t tmp; if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_framebuffer32)) || get_user(tmp, &up->base) || - get_user(kp->capability, &up->capability) || - get_user(kp->flags, &up->flags)) + put_user((__force void *)compat_ptr(tmp), &kp->base) || + convert_in_user(&up->capability, &kp->capability) || + convert_in_user(&up->flags, &kp->flags) || + get_v4l2_pix_format(&kp->fmt, &up->fmt)) return -EFAULT; - kp->base = compat_ptr(tmp); - get_v4l2_pix_format(&kp->fmt, &up->fmt); return 0; } -static int put_v4l2_framebuffer32(struct v4l2_framebuffer *kp, struct v4l2_framebuffer32 __user *up) +static int put_v4l2_framebuffer32(struct v4l2_framebuffer __user *kp, struct v4l2_framebuffer32 __user *up) { - u32 tmp = (u32)((unsigned long)kp->base); + void *base; if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_framebuffer32)) || - put_user(tmp, &up->base) || - put_user(kp->capability, &up->capability) || - put_user(kp->flags, &up->flags)) + get_user(base, &kp->base) || + put_user(ptr_to_compat(base), &up->base) || + convert_in_user(&kp->capability, &up->capability) || + convert_in_user(&kp->flags, &up->flags) || + put_v4l2_pix_format(&kp->fmt, &up->fmt)) return -EFAULT; - put_v4l2_pix_format(&kp->fmt, &up->fmt); return 0; } @@ -594,16 +700,16 @@ struct v4l2_input32 { /* The 64-bit v4l2_input struct has extra padding at the end of the struct. Otherwise it is identical to the 32-bit version. */ -static inline int get_v4l2_input32(struct v4l2_input *kp, struct v4l2_input32 __user *up) +static inline int get_v4l2_input32(struct v4l2_input __user *kp, struct v4l2_input32 __user *up) { - if (copy_from_user(kp, up, sizeof(struct v4l2_input32))) + if (copy_in_user(kp, up, sizeof(struct v4l2_input32))) return -EFAULT; return 0; } -static inline int put_v4l2_input32(struct v4l2_input *kp, struct v4l2_input32 __user *up) +static inline int put_v4l2_input32(struct v4l2_input __user *kp, struct v4l2_input32 __user *up) { - if (copy_to_user(up, kp, sizeof(struct v4l2_input32))) + if (copy_in_user(up, kp, sizeof(struct v4l2_input32))) return -EFAULT; return 0; } @@ -644,33 +750,50 @@ static inline int ctrl_is_pointer(u32 id) } } -static int get_v4l2_ext_controls32(struct v4l2_ext_controls *kp, struct v4l2_ext_controls32 __user *up) +static int bufsize_v4l2_ext_controls32(struct v4l2_ext_controls32 __user *up) +{ + __u32 count; + + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_ext_controls32)) || + get_user(count, &up->count)) + return -EFAULT; + if (count > V4L2_CID_MAX_CTRLS) + return -EINVAL; + return count * sizeof(struct v4l2_ext_control); +} + +static int get_v4l2_ext_controls32(struct v4l2_ext_controls __user *kp, struct + v4l2_ext_controls32 __user *up, void __user *aux_buf, + int aux_space) { struct v4l2_ext_control32 __user *ucontrols; struct v4l2_ext_control __user *kcontrols; - int n; + __u32 count; + unsigned int n; compat_caddr_t p; if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_ext_controls32)) || - get_user(kp->ctrl_class, &up->ctrl_class) || - get_user(kp->count, &up->count) || - get_user(kp->error_idx, &up->error_idx) || - copy_from_user(kp->reserved, up->reserved, sizeof(kp->reserved))) + convert_in_user(&up->ctrl_class, &kp->ctrl_class) || + get_user(count, &up->count) || + put_user(count, &kp->count) || + convert_in_user(&up->error_idx, &kp->error_idx) || + copy_in_user(kp->reserved, up->reserved, sizeof(kp->reserved))) return -EFAULT; - n = kp->count; - if (n == 0) { - kp->controls = NULL; - return 0; - } + if (count == 0) + return put_user(NULL, &kp->controls); if (get_user(p, &up->controls)) return -EFAULT; ucontrols = compat_ptr(p); if (!access_ok(VERIFY_READ, ucontrols, - n * sizeof(struct v4l2_ext_control32))) + count * sizeof(struct v4l2_ext_control32))) + return -EFAULT; + if (aux_space < count * sizeof(struct v4l2_ext_control)) return -EFAULT; - kcontrols = compat_alloc_user_space(n * sizeof(struct v4l2_ext_control)); - kp->controls = kcontrols; - while (--n >= 0) { + kcontrols = aux_buf; + if (put_user((__force struct v4l2_ext_control *)kcontrols, + &kp->controls)) + return -EFAULT; + for (n = 0; n < count; n++) { if (copy_in_user(kcontrols, ucontrols, sizeof(*ucontrols))) return -EFAULT; if (ctrl_is_pointer(kcontrols->id)) { @@ -688,30 +811,33 @@ static int get_v4l2_ext_controls32(struct v4l2_ext_controls *kp, struct v4l2_ext return 0; } -static int put_v4l2_ext_controls32(struct v4l2_ext_controls *kp, struct v4l2_ext_controls32 __user *up) +static int put_v4l2_ext_controls32(struct v4l2_ext_controls __user *kp, struct v4l2_ext_controls32 __user *up) { struct v4l2_ext_control32 __user *ucontrols; - struct v4l2_ext_control __user *kcontrols = kp->controls; - int n = kp->count; + struct v4l2_ext_control __user *kcontrols; + __u32 count; + unsigned int n; compat_caddr_t p; if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_ext_controls32)) || - put_user(kp->ctrl_class, &up->ctrl_class) || - put_user(kp->count, &up->count) || - put_user(kp->error_idx, &up->error_idx) || - copy_to_user(up->reserved, kp->reserved, sizeof(up->reserved))) + get_user(kcontrols, &kp->controls) || + convert_in_user(&kp->ctrl_class, &up->ctrl_class) || + get_user(count, &kp->count) || + put_user(count, &up->count) || + convert_in_user(&kp->error_idx, &up->error_idx) || + copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved))) return -EFAULT; - if (!kp->count) + if (!count) return 0; if (get_user(p, &up->controls)) return -EFAULT; ucontrols = compat_ptr(p); if (!access_ok(VERIFY_WRITE, ucontrols, - n * sizeof(struct v4l2_ext_control32))) + count * sizeof(struct v4l2_ext_control32))) return -EFAULT; - while (--n >= 0) { + for (n = 0; n < count; n++) { unsigned size = sizeof(*ucontrols); /* Do not modify the pointer when copying a pointer control. @@ -740,16 +866,17 @@ struct v4l2_event32 { __u32 reserved[8]; }; -static int put_v4l2_event32(struct v4l2_event *kp, struct v4l2_event32 __user *up) +static int put_v4l2_event32(struct v4l2_event __user *kp, struct v4l2_event32 __user *up) { if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_event32)) || - put_user(kp->type, &up->type) || - copy_to_user(&up->u, &kp->u, sizeof(kp->u)) || - put_user(kp->pending, &up->pending) || - put_user(kp->sequence, &up->sequence) || - put_compat_timespec(&kp->timestamp, &up->timestamp) || - put_user(kp->id, &up->id) || - copy_to_user(up->reserved, kp->reserved, 8 * sizeof(__u32))) + convert_in_user(&kp->type, &up->type) || + copy_in_user(&up->u, &kp->u, sizeof(kp->u)) || + convert_in_user(&kp->pending, &up->pending) || + convert_in_user(&kp->sequence, &up->sequence) || + convert_in_user(&kp->timestamp.tv_sec, &up->timestamp.tv_sec) || + convert_in_user(&kp->timestamp.tv_nsec, &up->timestamp.tv_nsec) || + convert_in_user(&kp->id, &up->id) || + copy_in_user(up->reserved, kp->reserved, 8 * sizeof(__u32))) return -EFAULT; return 0; } @@ -762,31 +889,32 @@ struct v4l2_subdev_edid32 { compat_caddr_t edid; }; -static int get_v4l2_subdev_edid32(struct v4l2_subdev_edid *kp, struct v4l2_subdev_edid32 __user *up) +static int get_v4l2_subdev_edid32(struct v4l2_subdev_edid __user *kp, struct v4l2_subdev_edid32 __user *up) { - u32 tmp; + compat_uptr_t tmp; if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_subdev_edid32)) || - get_user(kp->pad, &up->pad) || - get_user(kp->start_block, &up->start_block) || - get_user(kp->blocks, &up->blocks) || + convert_in_user(&up->pad, &kp->pad) || + convert_in_user(&up->start_block, &kp->start_block) || + convert_in_user(&up->blocks, &kp->blocks) || get_user(tmp, &up->edid) || - copy_from_user(kp->reserved, up->reserved, sizeof(kp->reserved))) + put_user(compat_ptr(tmp), &kp->edid) || + copy_in_user(kp->reserved, up->reserved, sizeof(kp->reserved))) return -EFAULT; - kp->edid = compat_ptr(tmp); return 0; } -static int put_v4l2_subdev_edid32(struct v4l2_subdev_edid *kp, struct v4l2_subdev_edid32 __user *up) +static int put_v4l2_subdev_edid32(struct v4l2_subdev_edid __user *kp, struct v4l2_subdev_edid32 __user *up) { - u32 tmp = (u32)((unsigned long)kp->edid); + void *edid; if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_subdev_edid32)) || - put_user(kp->pad, &up->pad) || - put_user(kp->start_block, &up->start_block) || - put_user(kp->blocks, &up->blocks) || - put_user(tmp, &up->edid) || - copy_to_user(kp->reserved, up->reserved, sizeof(kp->reserved))) + convert_in_user(&kp->pad, &up->pad) || + convert_in_user(&kp->start_block, &up->start_block) || + convert_in_user(&kp->blocks, &up->blocks) || + get_user(edid, &kp->edid) || + put_user(ptr_to_compat(edid), &up->edid) || + copy_in_user(up->reserved, kp->reserved, sizeof(up->reserved))) return -EFAULT; return 0; } @@ -819,22 +947,37 @@ static int put_v4l2_subdev_edid32(struct v4l2_subdev_edid *kp, struct v4l2_subde #define VIDIOC_G_OUTPUT32 _IOR ('V', 46, s32) #define VIDIOC_S_OUTPUT32 _IOWR('V', 47, s32) +/* + * Note that these macros contain return statements to avoid the need for the + * "caller" to check return values. + */ +#define ALLOC_USER_SPACE(size) \ +({ \ + void __user *up_native; \ + up_native = compat_alloc_user_space(size); \ + if (!up_native) \ + return -ENOMEM; \ + if (clear_user(up_native, size)) \ + return -EFAULT; \ + up_native; \ +}) + +#define ALLOC_AND_GET(bufsizefunc, getfunc, structname) \ + do { \ + aux_space = bufsizefunc(up); \ + if (aux_space < 0) \ + return aux_space; \ + up_native = ALLOC_USER_SPACE(sizeof(struct structname) + aux_space); \ + aux_buf = up_native + sizeof(struct structname); \ + err = getfunc(up_native, up, aux_buf, aux_space); \ + } while (0) + static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - union { - struct v4l2_format v2f; - struct v4l2_buffer v2b; - struct v4l2_framebuffer v2fb; - struct v4l2_input v2i; - struct v4l2_standard v2s; - struct v4l2_ext_controls v2ecs; - struct v4l2_event v2ev; - struct v4l2_create_buffers v2crt; - struct v4l2_subdev_edid v2edid; - unsigned long vx; - int vi; - } karg; void __user *up = compat_ptr(arg); + void __user *up_native = NULL; + void __user *aux_buf; + int aux_space; int compatible_arg = 1; long err = 0; @@ -873,30 +1016,35 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_STREAMOFF: case VIDIOC_S_INPUT: case VIDIOC_S_OUTPUT: - err = get_user(karg.vi, (s32 __user *)up); + up_native = ALLOC_USER_SPACE(sizeof(unsigned __user)); + if (convert_in_user((compat_uint_t __user *)up, + (unsigned __user *) up_native)) + return -EFAULT; compatible_arg = 0; break; case VIDIOC_G_INPUT: case VIDIOC_G_OUTPUT: + up_native = ALLOC_USER_SPACE(sizeof(unsigned __user)); compatible_arg = 0; break; case VIDIOC_SUBDEV_G_EDID: case VIDIOC_SUBDEV_S_EDID: - err = get_v4l2_subdev_edid32(&karg.v2edid, up); + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_subdev_edid)); + err = get_v4l2_subdev_edid32(up_native, up); compatible_arg = 0; break; case VIDIOC_G_FMT: case VIDIOC_S_FMT: case VIDIOC_TRY_FMT: - err = get_v4l2_format32(&karg.v2f, up); + ALLOC_AND_GET(bufsize_v4l2_format32, get_v4l2_format32, v4l2_format); compatible_arg = 0; break; case VIDIOC_CREATE_BUFS: - err = get_v4l2_create32(&karg.v2crt, up); + ALLOC_AND_GET(bufsize_v4l2_create32, get_v4l2_create32, v4l2_create_buffers); compatible_arg = 0; break; @@ -904,36 +1052,41 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_QUERYBUF: case VIDIOC_QBUF: case VIDIOC_DQBUF: - err = get_v4l2_buffer32(&karg.v2b, up); + ALLOC_AND_GET(bufsize_v4l2_buffer32, get_v4l2_buffer32, v4l2_buffer); compatible_arg = 0; break; case VIDIOC_S_FBUF: - err = get_v4l2_framebuffer32(&karg.v2fb, up); + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_framebuffer)); + err = get_v4l2_framebuffer32(up_native, up); compatible_arg = 0; break; case VIDIOC_G_FBUF: + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_framebuffer)); compatible_arg = 0; break; case VIDIOC_ENUMSTD: - err = get_v4l2_standard32(&karg.v2s, up); + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_standard)); + err = get_v4l2_standard32(up_native, up); compatible_arg = 0; break; case VIDIOC_ENUMINPUT: - err = get_v4l2_input32(&karg.v2i, up); + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_input)); + err = get_v4l2_input32(up_native, up); compatible_arg = 0; break; case VIDIOC_G_EXT_CTRLS: case VIDIOC_S_EXT_CTRLS: case VIDIOC_TRY_EXT_CTRLS: - err = get_v4l2_ext_controls32(&karg.v2ecs, up); + ALLOC_AND_GET(bufsize_v4l2_ext_controls32, get_v4l2_ext_controls32, v4l2_ext_controls); compatible_arg = 0; break; case VIDIOC_DQEVENT: + up_native = ALLOC_USER_SPACE(sizeof(struct v4l2_event)); compatible_arg = 0; break; } @@ -942,13 +1095,8 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar if (compatible_arg) err = native_ioctl(file, cmd, (unsigned long)up); - else { - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - err = native_ioctl(file, cmd, (unsigned long)&karg); - set_fs(old_fs); - } + else + err = native_ioctl(file, cmd, (unsigned long)up_native); /* Special case: even after an error we need to put the results back for these ioctls since the error_idx will @@ -957,7 +1105,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_G_EXT_CTRLS: case VIDIOC_S_EXT_CTRLS: case VIDIOC_TRY_EXT_CTRLS: - if (put_v4l2_ext_controls32(&karg.v2ecs, up)) + if (put_v4l2_ext_controls32(up_native, up)) err = -EFAULT; break; } @@ -969,44 +1117,45 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_S_OUTPUT: case VIDIOC_G_INPUT: case VIDIOC_G_OUTPUT: - err = put_user(((s32)karg.vi), (s32 __user *)up); + err = convert_in_user(((unsigned __user *)up_native), + (compat_uint_t __user *)up); break; case VIDIOC_G_FBUF: - err = put_v4l2_framebuffer32(&karg.v2fb, up); + err = put_v4l2_framebuffer32(up_native, up); break; case VIDIOC_DQEVENT: - err = put_v4l2_event32(&karg.v2ev, up); + err = put_v4l2_event32(up_native, up); break; case VIDIOC_SUBDEV_G_EDID: case VIDIOC_SUBDEV_S_EDID: - err = put_v4l2_subdev_edid32(&karg.v2edid, up); + err = put_v4l2_subdev_edid32(up_native, up); break; case VIDIOC_G_FMT: case VIDIOC_S_FMT: case VIDIOC_TRY_FMT: - err = put_v4l2_format32(&karg.v2f, up); + err = put_v4l2_format32(up_native, up); break; case VIDIOC_CREATE_BUFS: - err = put_v4l2_create32(&karg.v2crt, up); + err = put_v4l2_create32(up_native, up); break; case VIDIOC_QUERYBUF: case VIDIOC_QBUF: case VIDIOC_DQBUF: - err = put_v4l2_buffer32(&karg.v2b, up); + err = put_v4l2_buffer32(up_native, up); break; case VIDIOC_ENUMSTD: - err = put_v4l2_standard32(&karg.v2s, up); + err = put_v4l2_standard32(up_native, up); break; case VIDIOC_ENUMINPUT: - err = put_v4l2_input32(&karg.v2i, up); + err = put_v4l2_input32(up_native, up); break; } return err; |
