[BLOCK] scsi_ioctl: file can be NULL from ioctl_by_bdev()
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index c2ac36d..18de84c 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -190,16 +190,21 @@
safe_for_write(GPCMD_SET_STREAMING),
};
unsigned char type = cmd_type[cmd[0]];
+ int has_write_perm = 0;
/* Anybody who can open the device can do a read-safe command */
if (type & CMD_READ_SAFE)
return 0;
+ /*
+ * file can be NULL from ioctl_by_bdev()...
+ */
+ if (file)
+ has_write_perm = file->f_mode & FMODE_WRITE;
+
/* Write-safe commands just require a writable open.. */
- if (type & CMD_WRITE_SAFE) {
- if (file->f_mode & FMODE_WRITE)
- return 0;
- }
+ if ((type & CMD_WRITE_SAFE) && has_write_perm)
+ return 0;
/* And root can do any command.. */
if (capable(CAP_SYS_RAWIO))