5.10-stable review patch. If anyone has any objections, please let me know.
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From: Ondrej Mosnacek omosnace@redhat.com
[ Upstream commit 9f36169912331fa035d7b73a91252d7c2512eb1a ]
As evident from the definition of ip_options_get(), the IP option IPOPT_END is used to pad the IP option data array, not IPOPT_NOP. Yet the loop that walks the IP options to determine the total IP options length in cipso_v4_delopt() doesn't take IPOPT_END into account.
Fix it by recognizing the IPOPT_END value as the end of actual options.
Fixes: 014ab19a69c3 ("selinux: Set socket NetLabel based on connection endpoint") Signed-off-by: Ondrej Mosnacek omosnace@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/cipso_ipv4.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index d4a4160159a92..c5da958e3bbdb 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -2016,12 +2016,16 @@ static int cipso_v4_delopt(struct ip_options_rcu __rcu **opt_ptr) * from there we can determine the new total option length */ iter = 0; optlen_new = 0; - while (iter < opt->opt.optlen) - if (opt->opt.__data[iter] != IPOPT_NOP) { + while (iter < opt->opt.optlen) { + if (opt->opt.__data[iter] == IPOPT_END) { + break; + } else if (opt->opt.__data[iter] == IPOPT_NOP) { + iter++; + } else { iter += opt->opt.__data[iter + 1]; optlen_new = iter; - } else - iter++; + } + } hdr_delta = opt->opt.optlen; opt->opt.optlen = (optlen_new + 3) & ~3; hdr_delta -= opt->opt.optlen;