cxgb4: Fix stack out-of-bounds read due to wrong size to t4_record_mbox()
authorStefano Brivio <sbrivio@redhat.com>
Fri, 25 Aug 2017 20:48:48 +0000 (22:48 +0200)
committerDavid S. Miller <davem@davemloft.net>
Mon, 28 Aug 2017 22:24:23 +0000 (15:24 -0700)
commit0f3086868e8889a823a6e0f3d299102aa895d947
treee81f78377205b36efdf7715495fba0ae616d0371
parentad4540cc5aa3dccb8e1e12458d57f8c40fae5a1c
cxgb4: Fix stack out-of-bounds read due to wrong size to t4_record_mbox()

Passing commands for logging to t4_record_mbox() with size
MBOX_LEN, when the actual command size is actually smaller,
causes out-of-bounds stack accesses in t4_record_mbox() while
copying command words here:

for (i = 0; i < size / 8; i++)
entry->cmd[i] = be64_to_cpu(cmd[i]);

Up to 48 bytes from the stack are then leaked to debugfs.

This happens whenever we send (and log) commands described by
structs fw_sched_cmd (32 bytes leaked), fw_vi_rxmode_cmd (48),
fw_hello_cmd (48), fw_bye_cmd (48), fw_initialize_cmd (48),
fw_reset_cmd (48), fw_pfvf_cmd (32), fw_eq_eth_cmd (16),
fw_eq_ctrl_cmd (32), fw_eq_ofld_cmd (32), fw_acl_mac_cmd(16),
fw_rss_glb_config_cmd(32), fw_rss_vi_config_cmd(32),
fw_devlog_cmd(32), fw_vi_enable_cmd(48), fw_port_cmd(32),
fw_sched_cmd(32), fw_devlog_cmd(32).

The cxgb4vf driver got this right instead.

When we call t4_record_mbox() to log a command reply, a MBOX_LEN
size can be used though, as get_mbox_rpl() will fill cmd_rpl up
completely.

Fixes: 7f080c3f2ff0 ("cxgb4: Add support to enable logging of firmware mailbox commands")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/chelsio/cxgb4/t4_hw.c