6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: He Zhe <zhe.he@xxxxxxxxxxxxx>
commit 4e60131d0d36af65ab9c9144f4f163fe97ae36e8 upstream.
hpet_compat_ioctl and read file operations failed to handle parameters from
32-bit userspace and thus samples/timers/hpet_example.c fails as below.
root@intel-x86-64:~# ./hpet_example-32.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: HPET_IRQFREQ failed
This patch fixes cmd and arg handling in hpet_compat_ioctl and adds compat
handling for 32-bit userspace in hpet_read.
hpet_example now shows that it works for both 64-bit and 32-bit.
root@intel-x86-64:~# ./hpet_example-32.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: info.hi_flags 0x0
hpet_poll: expired time = 0xf4298
hpet_poll: revents = 0x1
hpet_poll: data 0x1
hpet_poll: expired time = 0xf4235
hpet_poll: revents = 0x1
hpet_poll: data 0x1
root@intel-x86-64:~# ./hpet_example-64.out poll /dev/hpet 1 2
-hpet: executing poll
hpet_poll: info.hi_flags 0x0
hpet_poll: expired time = 0xf42a1
hpet_poll: revents = 0x1
hpet_poll: data 0x1
hpet_poll: expired time = 0xf4232
hpet_poll: revents = 0x1
hpet_poll: data 0x1
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx>
Fixes: 54066a57c584 ("hpet: kill BKL, add compat_ioctl")
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://lore.kernel.org/r/20240606123908.738733-1-zhe.he@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/hpet.c | 34 +++++++++++++++++++++++++++++-----
1 file changed, 29 insertions(+), 5 deletions(-)
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -289,8 +289,13 @@ hpet_read(struct file *file, char __user
if (!devp->hd_ireqfreq)
return -EIO;
- if (count < sizeof(unsigned long))
- return -EINVAL;
+ if (in_compat_syscall()) {
+ if (count < sizeof(compat_ulong_t))
+ return -EINVAL;
+ } else {
+ if (count < sizeof(unsigned long))
+ return -EINVAL;
+ }
add_wait_queue(&devp->hd_waitqueue, &wait);
@@ -314,9 +319,16 @@ hpet_read(struct file *file, char __user
schedule();
}
- retval = put_user(data, (unsigned long __user *)buf);
- if (!retval)
- retval = sizeof(unsigned long);
+ if (in_compat_syscall()) {
+ retval = put_user(data, (compat_ulong_t __user *)buf);
+ if (!retval)
+ retval = sizeof(compat_ulong_t);
+ } else {
+ retval = put_user(data, (unsigned long __user *)buf);
+ if (!retval)
+ retval = sizeof(unsigned long);
+ }
+
out:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&devp->hd_waitqueue, &wait);
@@ -671,12 +683,24 @@ struct compat_hpet_info {
unsigned short hi_timer;
};
+/* 32-bit types would lead to different command codes which should be
+ * translated into 64-bit ones before passed to hpet_ioctl_common
+ */
+#define COMPAT_HPET_INFO _IOR('h', 0x03, struct compat_hpet_info)
+#define COMPAT_HPET_IRQFREQ _IOW('h', 0x6, compat_ulong_t)
+
static long
hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct hpet_info info;
int err;
+ if (cmd == COMPAT_HPET_INFO)
+ cmd = HPET_INFO;
+
+ if (cmd == COMPAT_HPET_IRQFREQ)
+ cmd = HPET_IRQFREQ;
+
mutex_lock(&hpet_mutex);
err = hpet_ioctl_common(file->private_data, cmd, arg, &info);
mutex_unlock(&hpet_mutex);
