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| author | Dave Airlie <airlied@redhat.com> | 2018-11-29 01:34:03 +0100 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2018-11-29 01:34:03 +0100 |
| commit | 1ec28f8b8ada4e4f77d1af006a3a474f4f83b8e3 (patch) | |
| tree | 2e810e02a66cdec0bc82a8555796b7083ad03416 /drivers/hid/uhid.c | |
| parent | Merge tag 'drm-misc-next-2018-11-28' of git://anongit.freedesktop.org/drm/drm... (diff) | |
| parent | Linux 4.20-rc4 (diff) | |
| download | linux-1ec28f8b8ada4e4f77d1af006a3a474f4f83b8e3.tar.xz linux-1ec28f8b8ada4e4f77d1af006a3a474f4f83b8e3.zip | |
Merge v4.20-rc4 into drm-next
Requested by Boris Brezillon for some vc4 fixes that are needed for future vc4 work.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/hid/uhid.c')
| -rw-r--r-- | drivers/hid/uhid.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index 3c5507313606..840634e0f1e3 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -12,6 +12,7 @@ #include <linux/atomic.h> #include <linux/compat.h> +#include <linux/cred.h> #include <linux/device.h> #include <linux/fs.h> #include <linux/hid.h> @@ -496,12 +497,13 @@ static int uhid_dev_create2(struct uhid_device *uhid, goto err_free; } - len = min(sizeof(hid->name), sizeof(ev->u.create2.name)); - strlcpy(hid->name, ev->u.create2.name, len); - len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)); - strlcpy(hid->phys, ev->u.create2.phys, len); - len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)); - strlcpy(hid->uniq, ev->u.create2.uniq, len); + /* @hid is zero-initialized, strncpy() is correct, strlcpy() not */ + len = min(sizeof(hid->name), sizeof(ev->u.create2.name)) - 1; + strncpy(hid->name, ev->u.create2.name, len); + len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)) - 1; + strncpy(hid->phys, ev->u.create2.phys, len); + len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)) - 1; + strncpy(hid->uniq, ev->u.create2.uniq, len); hid->ll_driver = &uhid_hid_driver; hid->bus = ev->u.create2.bus; @@ -722,6 +724,17 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer, switch (uhid->input_buf.type) { case UHID_CREATE: + /* + * 'struct uhid_create_req' contains a __user pointer which is + * copied from, so it's unsafe to allow this with elevated + * privileges (e.g. from a setuid binary) or via kernel_write(). + */ + if (file->f_cred != current_cred() || uaccess_kernel()) { + pr_err_once("UHID_CREATE from different security context by process %d (%s), this is not allowed.\n", + task_tgid_vnr(current), current->comm); + ret = -EACCES; + goto unlock; + } ret = uhid_dev_create(uhid, &uhid->input_buf); break; case UHID_CREATE2: |