From ef87dbe7614341c2e7bfe8d32fcb7028cc97442c Mon Sep 17 00:00:00 2001 From: Matthew Daley Date: Mon, 28 Apr 2014 19:05:20 +1200 Subject: floppy: ignore kernel-only members in FDRAWCMD ioctl input Always clear out these floppy_raw_cmd struct members after copying the entire structure from userspace so that the in-kernel version is always valid and never left in an interdeterminate state. Signed-off-by: Matthew Daley Signed-off-by: Linus Torvalds --- drivers/block/floppy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/block/floppy.c') diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 8f5565bf34cd..12251a688871 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3121,10 +3121,11 @@ loop: return -ENOMEM; *rcmd = ptr; ret = copy_from_user(ptr, param, sizeof(*ptr)); - if (ret) - return -EFAULT; ptr->next = NULL; ptr->buffer_length = 0; + ptr->kernel_data = NULL; + if (ret) + return -EFAULT; param += sizeof(struct floppy_raw_cmd); if (ptr->cmd_count > 33) /* the command may now also take up the space @@ -3140,7 +3141,6 @@ loop: for (i = 0; i < 16; i++) ptr->reply[i] = 0; ptr->resultcode = 0; - ptr->kernel_data = NULL; if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) { if (ptr->length <= 0) -- cgit v1.2.3 From 2145e15e0557a01b9195d1c7199a1b92cb9be81f Mon Sep 17 00:00:00 2001 From: Matthew Daley Date: Mon, 28 Apr 2014 19:05:21 +1200 Subject: floppy: don't write kernel-only members to FDRAWCMD ioctl output Do not leak kernel-only floppy_raw_cmd structure members to userspace. This includes the linked-list pointer and the pointer to the allocated DMA space. Signed-off-by: Matthew Daley Signed-off-by: Linus Torvalds --- drivers/block/floppy.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/block/floppy.c') diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 12251a688871..fa9bb742df6e 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3067,7 +3067,10 @@ static int raw_cmd_copyout(int cmd, void __user *param, int ret; while (ptr) { - ret = copy_to_user(param, ptr, sizeof(*ptr)); + struct floppy_raw_cmd cmd = *ptr; + cmd.next = NULL; + cmd.kernel_data = NULL; + ret = copy_to_user(param, &cmd, sizeof(cmd)); if (ret) return -EFAULT; param += sizeof(struct floppy_raw_cmd); -- cgit v1.2.3