From: Vladimir Oltean Date: Thu, 20 Nov 2025 06:12:31 +0000 (+0800) Subject: net: dsa: sja1105: fix kasan out-of-bounds warning in sja1105_table_delete_entry() X-Git-Tag: v6.12.59~80 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=031e00249e9e6bee72ba66701c8f83b45fc4b8a2;p=thirdparty%2Fkernel%2Fstable.git net: dsa: sja1105: fix kasan out-of-bounds warning in sja1105_table_delete_entry() [ Upstream commit 5f2b28b79d2d1946ee36ad8b3dc0066f73c90481 ] 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: 6666cebc5e30 ("net: dsa: sja1105: Add support for VLAN operations") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250318115716.2124395-4-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Chen Yu Signed-off-by: Sasha Levin --- diff --git a/drivers/net/dsa/sja1105/sja1105_static_config.c b/drivers/net/dsa/sja1105/sja1105_static_config.c index baba204ad62f6..2ac91fe2a79bc 100644 --- a/drivers/net/dsa/sja1105/sja1105_static_config.c +++ b/drivers/net/dsa/sja1105/sja1105_static_config.c @@ -1921,8 +1921,10 @@ int sja1105_table_delete_entry(struct sja1105_table *table, int i) if (i > table->entry_count) return -ERANGE; - memmove(entries + i * entry_size, entries + (i + 1) * entry_size, - (table->entry_count - i) * entry_size); + if (i + 1 < table->entry_count) { + memmove(entries + i * entry_size, entries + (i + 1) * entry_size, + (table->entry_count - i - 1) * entry_size); + } table->entry_count--;