netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case

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[ Upstream commit 1e3a359316 ]

In decode_int(), the CONS case calls get_bits(bs, 2) to read a length
value, then calls get_uint(bs, len) without checking that len bytes
remain in the buffer. The existing boundary check only validates the
2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint()
reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte
slab-out-of-bounds read.

Add a boundary check for len bytes after get_bits() and before
get_uint().

Fixes: 5e35941d99 ("[NETFILTER]: Add H.323 conntrack/NAT helper")
Reported-by: Klaudia Kloc <klaudia@vidocsecurity.com>
Reported-by: Dawid Moczadło <dawid@vidocsecurity.com>
Signed-off-by: Jenny Guanni Qu <qguanni@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Jenny Guanni Qu 2026-03-12 02:29:32 +00:00 • committed by Greg Kroah-Hartman

parent cd1b7403ec

commit c95dc674eb

1 changed files with 2 additions and 0 deletions

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net/netfilter/nf_conntrack_h323_asn1.c

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