[PATCH 5.10 456/491] netlink: add nla be16/32 types to minlen array

Greg Kroah-Hartman
2026-04-13T17:03:31Z

From: Florian Westphal <fw@strlen.de>

commit 9a0d18853c280f6a0ee99f91619f2442a17a323a upstream.

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>
Link: https://lore.kernel.org/r/20240221172740.5092-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
lib/nlattr.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -30,6 +30,8 @@ static const u8 nla_attr_len[NLA_TYPE_MA
[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
[NLA_S16] = sizeof(s16),
[NLA_S32] = sizeof(s32),
[NLA_S64] = sizeof(s64),
+ [NLA_BE16] = sizeof(__be16),
+ [NLA_BE32] = sizeof(__be32),
};

/*