[PATCH net] netlink: add nla be16/32 types to minlen array

[Florian Westphal <fw@strlen.de>]

BUG: KMSAN: uninit-value in nla_validate_range_unsigned lib/nlattr.c:222 [inline]
BUG: KMSAN: uninit-value in nla_validate_int_range lib/nlattr.c:336 [inline]
BUG: KMSAN: uninit-value in validate_nla lib/nlattr.c:575 [inline]
BUG: KMSAN: uninit-value in __nla_validate_parse+0x2e20/0x45c0 lib/nlattr.c:631
 nla_validate_range_unsigned lib/nlattr.c:222 [inline]
 nla_validate_int_range lib/nlattr.c:336 [inline]
 validate_nla lib/nlattr.c:575 [inline]
...

The message in question matches this policy:

 [NFTA_TARGET_REV]       = NLA_POLICY_MAX(NLA_BE32, 255),

but because NLA_BE32 size in minlen array is 0, the validation
code will read past the malformed (too small) attribute.

Note: Other attributes, e.g. BITFIELD32, SINT, UINT.. are also missing:
those likely should be added too.

Reported-by: syzbot+3f497b07aa3baf2fb4d0@syzkaller.appspotmail.com
Reported-by: xingwei lee <xrivendell7@gmail.com>
Closes: https://lore.kernel.org/all/CABOYnLzFYHSnvTyS6zGa-udNX55+izqkOt2sB9WDqUcEGW6n8w@mail.gmail.com/raw
Fixes: ecaf75ffd5f5 ("netlink: introduce bigendian integer types")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 lib/nlattr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/nlattr.c b/lib/nlattr.c
index ed2ab43e1b22..be9c576b6e2d 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -30,6 +30,8 @@ static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
 	[NLA_S16]	= sizeof(s16),
 	[NLA_S32]	= sizeof(s32),
 	[NLA_S64]	= sizeof(s64),
+	[NLA_BE16]	= sizeof(__be16),
+	[NLA_BE32]	= sizeof(__be32),
 };
 
 static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
@@ -43,6 +45,8 @@ static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
 	[NLA_S16]	= sizeof(s16),
 	[NLA_S32]	= sizeof(s32),
 	[NLA_S64]	= sizeof(s64),
+	[NLA_BE16]	= sizeof(__be16),
+	[NLA_BE32]	= sizeof(__be32),
 };
 
 /*
-- 
2.43.0