Commit a1f74ae8 authored by Dan Rosenberg's avatar Dan Rosenberg Committed by James Bottomley

[SCSI] mpt2sas: prevent heap overflows and unchecked reads

At two points in handling device ioctls via /dev/mpt2ctl, user-supplied
length values are used to copy data from userspace into heap buffers
without bounds checking, allowing controllable heap corruption and
subsequently privilege escalation.

Additionally, user-supplied values are used to determine the size of a
copy_to_user() as well as the offset into the buffer to be read, with no
bounds checking, allowing users to read arbitrary kernel memory.
Signed-off-by: default avatarDan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Acked-by: default avatarEric Moore <eric.moore@lsi.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent 686c4cbb
......@@ -688,6 +688,13 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc,
goto out;
}
/* Check for overflow and wraparound */
if (karg.data_sge_offset * 4 > ioc->request_sz ||
karg.data_sge_offset > (UINT_MAX / 4)) {
ret = -EINVAL;
goto out;
}
/* copy in request message frame from user */
if (copy_from_user(mpi_request, mf, karg.data_sge_offset*4)) {
printk(KERN_ERR "failure at %s:%d/%s()!\n", __FILE__, __LINE__,
......@@ -1963,7 +1970,7 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state)
Mpi2DiagBufferPostReply_t *mpi_reply;
int rc, i;
u8 buffer_type;
unsigned long timeleft;
unsigned long timeleft, request_size, copy_size;
u16 smid;
u16 ioc_status;
u8 issue_reset = 0;
......@@ -1999,6 +2006,8 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state)
return -ENOMEM;
}
request_size = ioc->diag_buffer_sz[buffer_type];
if ((karg.starting_offset % 4) || (karg.bytes_to_read % 4)) {
printk(MPT2SAS_ERR_FMT "%s: either the starting_offset "
"or bytes_to_read are not 4 byte aligned\n", ioc->name,
......@@ -2006,13 +2015,23 @@ _ctl_diag_read_buffer(void __user *arg, enum block_state state)
return -EINVAL;
}
if (karg.starting_offset > request_size)
return -EINVAL;
diag_data = (void *)(request_data + karg.starting_offset);
dctlprintk(ioc, printk(MPT2SAS_INFO_FMT "%s: diag_buffer(%p), "
"offset(%d), sz(%d)\n", ioc->name, __func__,
diag_data, karg.starting_offset, karg.bytes_to_read));
/* Truncate data on requests that are too large */
if ((diag_data + karg.bytes_to_read < diag_data) ||
(diag_data + karg.bytes_to_read > request_data + request_size))
copy_size = request_size - karg.starting_offset;
else
copy_size = karg.bytes_to_read;
if (copy_to_user((void __user *)uarg->diagnostic_data,
diag_data, karg.bytes_to_read)) {
diag_data, copy_size)) {
printk(MPT2SAS_ERR_FMT "%s: Unable to write "
"mpt_diag_read_buffer_t data @ %p\n", ioc->name,
__func__, diag_data);
......
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