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scsi: megaraid_sas: Simplify compat_ioctl handling

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There have been several attempts to fix serious problems in the compat
handling in megasas_mgmt_compat_ioctl_fw(), and it also uses the
compat_alloc_user_space() function.

Folding the compat handling into the regular ioctl function with
in_compat_syscall() simplifies it a lot and avoids some of the remaining
problems:

 - missing handling of unaligned pointers

 - overflowing the ioc->frame.raw array from invalid input

 - compat_alloc_user_space()

Link: https://lore.kernel.org/r/20201030164450.1253641-3-arnd@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Arnd Bergmann 2020-10-30 17:44:21 +01:00 committed by Martin K. Petersen
parent 381d34e376
commit bba84aecca
2 changed files with 46 additions and 74 deletions
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2
drivers/scsi/megaraid/megaraid_sas.h
View file

@ -2605,7 +2605,6 @@ struct megasas_aen {
u32 class_locale_word;
} __attribute__ ((packed));
#ifdef CONFIG_COMPAT
struct compat_megasas_iocpacket {
u16 host_no;
u16 __pad1;
@ -2621,7 +2620,6 @@ struct compat_megasas_iocpacket {
} __attribute__ ((packed));
#define MEGASAS_IOC_FIRMWARE32 _IOWR('M', 1, struct compat_megasas_iocpacket)
#endif
#define MEGASAS_IOC_FIRMWARE _IOWR('M', 1, struct megasas_iocpacket)
#define MEGASAS_IOC_GET_AEN _IOW('M', 3, struct megasas_aen)

118
drivers/scsi/megaraid/megaraid_sas_base.c
View file

@ -8319,16 +8319,19 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
* copy out the sense
*/
if (ioc->sense_len) {
void __user *uptr;
/*
* sense_ptr points to the location that has the user
* sense buffer address
*/
sense_ptr = (unsigned long *) ((unsigned long)ioc->frame.raw +
ioc->sense_off);
sense_ptr = (void *)ioc->frame.raw + ioc->sense_off;
if (in_compat_syscall())
uptr = compat_ptr(get_unaligned((compat_uptr_t *)
sense_ptr));
else
uptr = get_unaligned((void __user **)sense_ptr);
if (copy_to_user((void __user *)((unsigned long)
get_unaligned((unsigned long *)sense_ptr)),
sense, ioc->sense_len)) {
if (copy_to_user(uptr, sense, ioc->sense_len)) {
dev_err(&instance->pdev->dev, "Failed to copy out to user "
"sense data\n");
error = -EFAULT;
@ -8371,6 +8374,38 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
return error;
}
static struct megasas_iocpacket *
megasas_compat_iocpacket_get_user(void __user *arg)
{
struct megasas_iocpacket *ioc;
struct compat_megasas_iocpacket __user *cioc = arg;
size_t size;
int err = -EFAULT;
int i;
ioc = kzalloc(sizeof(*ioc), GFP_KERNEL);
if (!ioc)
return ERR_PTR(-ENOMEM);
size = offsetof(struct megasas_iocpacket, frame) + sizeof(ioc->frame);
if (copy_from_user(ioc, arg, size))
goto out;
for (i = 0; i < MAX_IOCTL_SGE; i++) {
compat_uptr_t iov_base;
if (get_user(iov_base, &cioc->sgl[i].iov_base) ||
get_user(ioc->sgl[i].iov_len, &cioc->sgl[i].iov_len))
goto out;
ioc->sgl[i].iov_base = compat_ptr(iov_base);
}
return ioc;
out:
kfree(ioc);
return ERR_PTR(err);
}
static int megasas_mgmt_ioctl_fw(struct file *file, unsigned long arg)
{
struct megasas_iocpacket __user *user_ioc =
@ -8379,7 +8414,11 @@ static int megasas_mgmt_ioctl_fw(struct file *file, unsigned long arg)
struct megasas_instance *instance;
int error;
ioc = memdup_user(user_ioc, sizeof(*ioc));
if (in_compat_syscall())
ioc = megasas_compat_iocpacket_get_user(user_ioc);
else
ioc = memdup_user(user_ioc, sizeof(struct megasas_iocpacket));
if (IS_ERR(ioc))
return PTR_ERR(ioc);
@ -8484,78 +8523,13 @@ megasas_mgmt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
#ifdef CONFIG_COMPAT
static int megasas_mgmt_compat_ioctl_fw(struct file *file, unsigned long arg)
{
struct compat_megasas_iocpacket __user *cioc =
(struct compat_megasas_iocpacket __user *)arg;
struct megasas_iocpacket __user *ioc =
compat_alloc_user_space(sizeof(struct megasas_iocpacket));
int i;
int error = 0;
compat_uptr_t ptr;
u32 local_sense_off;
u32 local_sense_len;
u32 user_sense_off;
if (clear_user(ioc, sizeof(*ioc)))
return -EFAULT;
if (copy_in_user(&ioc->host_no, &cioc->host_no, sizeof(u16)) ||
copy_in_user(&ioc->sgl_off, &cioc->sgl_off, sizeof(u32)) ||
copy_in_user(&ioc->sense_off, &cioc->sense_off, sizeof(u32)) ||
copy_in_user(&ioc->sense_len, &cioc->sense_len, sizeof(u32)) ||
copy_in_user(ioc->frame.raw, cioc->frame.raw, 128) ||
copy_in_user(&ioc->sge_count, &cioc->sge_count, sizeof(u32)))
return -EFAULT;
/*
* The sense_ptr is used in megasas_mgmt_fw_ioctl only when
* sense_len is not null, so prepare the 64bit value under
* the same condition.
*/
if (get_user(local_sense_off, &ioc->sense_off) ||
get_user(local_sense_len, &ioc->sense_len) ||
get_user(user_sense_off, &cioc->sense_off))
return -EFAULT;
if (local_sense_off != user_sense_off)
return -EINVAL;
if (local_sense_len) {
void __user **sense_ioc_ptr =
(void __user **)((u8 *)((unsigned long)&ioc->frame.raw) + local_sense_off);
compat_uptr_t *sense_cioc_ptr =
(compat_uptr_t *)(((unsigned long)&cioc->frame.raw) + user_sense_off);
if (get_user(ptr, sense_cioc_ptr) ||
put_user(compat_ptr(ptr), sense_ioc_ptr))
return -EFAULT;
}
for (i = 0; i < MAX_IOCTL_SGE; i++) {
if (get_user(ptr, &cioc->sgl[i].iov_base) ||
put_user(compat_ptr(ptr), &ioc->sgl[i].iov_base) ||
copy_in_user(&ioc->sgl[i].iov_len,
&cioc->sgl[i].iov_len, sizeof(compat_size_t)))
return -EFAULT;
}
error = megasas_mgmt_ioctl_fw(file, (unsigned long)ioc);
if (copy_in_user(&cioc->frame.hdr.cmd_status,
&ioc->frame.hdr.cmd_status, sizeof(u8))) {
printk(KERN_DEBUG "megasas: error copy_in_user cmd_status\n");
return -EFAULT;
}
return error;
}
static long
megasas_mgmt_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
switch (cmd) {
case MEGASAS_IOC_FIRMWARE32:
return megasas_mgmt_compat_ioctl_fw(file, arg);
return megasas_mgmt_ioctl_fw(file, arg);
case MEGASAS_IOC_GET_AEN:
return megasas_mgmt_ioctl_aen(file, arg);
}