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() Signed-off-by: Arnd Bergmann <[email protected]> --- drivers/scsi/megaraid/megaraid_sas_base.c | 123 ++++++++++------------ 1 file changed, 56 insertions(+), 67 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index c3de69f3bee8..601dab468823 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -8331,6 +8331,56 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, return error; } +static struct megasas_iocpacket *megasas_compat_iocpacket_get_user(void __user *arg) +{ + int err = -EFAULT; +#ifdef CONFIG_COMPAT + struct megasas_iocpacket *ioc; + struct compat_megasas_iocpacket __user *cioc = arg; + int i; + + ioc = kzalloc(sizeof(*ioc), GFP_KERNEL); + if (copy_from_user(ioc, arg, + offsetof(struct megasas_iocpacket, frame) + 128)) + goto out; + + /* + * 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 (ioc->sense_len) { + compat_uptr_t *sense_ioc_ptr; + void __user *sense_cioc; + + /* make sure the pointer is inside of frame.raw */ + if (ioc->sense_off > + (sizeof(ioc->frame.raw) - sizeof(void __user*))) { + err = -EINVAL; + goto out; + } + + sense_ioc_ptr = (compat_uptr_t *)&ioc->frame.raw[ioc->sense_off]; + sense_cioc = compat_ptr(get_unaligned(sense_ioc_ptr)); + put_unaligned((unsigned long)sense_cioc, (void **)sense_ioc_ptr); + } + + 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); +#endif + return ERR_PTR(err); +} + static int megasas_mgmt_ioctl_fw(struct file *file, unsigned long arg) { struct megasas_iocpacket __user *user_ioc = @@ -8339,7 +8389,11 @@ 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); @@ -8444,78 +8498,13 @@ 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); } -- 2.27.0
