Commit 5f2b28b7 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: dsa: sja1105: fix kasan out-of-bounds warning in sja1105_table_delete_entry() 



There are actually 2 problems:
- deleting the last element doesn't require the memmove of elements
  [i + 1, end) over it. Actually, element i+1 is out of bounds.
- The memmove itself should move size - i - 1 elements, because the last
  element is out of bounds.

The out-of-bounds element still remains out of bounds after being
accessed, so the problem is only that we touch it, not that it becomes
in active use. But I suppose it can lead to issues if the out-of-bounds
element is part of an unmapped page.

Fixes: 6666cebc ("net: dsa: sja1105: Add support for VLAN operations")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250318115716.2124395-4-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b6a177b5

drivers/net/dsa/sja1105/sja1105_static_config.c

+4 −2
Original line number Diff line number Diff line
@@ -1917,8 +1917,10 @@ int sja1105_table_delete_entry(struct sja1105_table *table, int i) 
	if (i > table->entry_count)

		return -ERANGE;



	if (i + 1 < table->entry_count) {

		memmove(entries + i * entry_size, entries + (i + 1) * entry_size,

		(table->entry_count - i) * entry_size);

			(table->entry_count - i - 1) * entry_size);

	}



	table->entry_count--;