Commit 9a0d1885 authored by Florian Westphal's avatar Florian Westphal Committed by Jakub Kicinski
Browse files

netlink: add nla be16/32 types to minlen array 



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: default avatar <syzbot+3f497b07aa3baf2fb4d0@syzkaller.appspotmail.com>
Reported-by: default avatarxingwei lee <xrivendell7@gmail.com>
Closes: https://lore.kernel.org/all/CABOYnLzFYHSnvTyS6zGa-udNX55+izqkOt2sB9WDqUcEGW6n8w@mail.gmail.com/raw


Fixes: ecaf75ff ("netlink: introduce bigendian integer types")
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20240221172740.5092-1-fw@strlen.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 661779e1

lib/nlattr.c

+4 −0
Original line number Diff line number Diff line
@@ -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),

};



/*