From: Bryam Vargas Date: Thu, 25 Jun 2026 11:54:09 +0000 (-0500) Subject: thunderbolt: Bound the DROM dual link port number before indexing sw->ports X-Git-Tag: v7.2-rc7~5^2~8^2~2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d6764992f17b23d91ff93ce905ab53c2aa7191f0;p=thirdparty%2Flinux.git thunderbolt: Bound the DROM dual link port number before indexing sw->ports tb_drom_parse_entry_port() validates the device-supplied header->index against sw->config.max_port_number before indexing sw->ports[], but the sibling field entry->dual_link_port_nr -- a 6-bit value also read from the DROM -- indexes the same array with no such check. A malicious or malformed Thunderbolt device can set dual_link_port_nr beyond the allocated sw->ports[] (max_port_number + 1 entries), producing an out-of-bounds tb_port pointer that is stored and later dereferenced. Reject a port entry whose dual_link_port_nr exceeds max_port_number, the same bound already applied to header->index. Fixes: cd22e73bdf5e ("thunderbolt: Read port configuration from eeprom.") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Signed-off-by: Mika Westerberg --- diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c index 5681c17f82ec..2a13fa6888ba 100644 --- a/drivers/thunderbolt/eeprom.c +++ b/drivers/thunderbolt/eeprom.c @@ -394,9 +394,16 @@ static int tb_drom_parse_entry_port(struct tb_switch *sw, return -EIO; } port->link_nr = entry->link_nr; - if (entry->has_dual_link_port) + if (entry->has_dual_link_port) { + if (entry->dual_link_port_nr > sw->config.max_port_number) { + tb_sw_warn(sw, + "port entry has invalid dual link port number %u\n", + entry->dual_link_port_nr); + return -EIO; + } port->dual_link_port = &port->sw->ports[entry->dual_link_port_nr]; + } } return 0; }