netfilter: bpf: reject invalid NAT manipulation types

Overview

In the Linux kernel, the following vulnerability has been resolved:

netfilter: bpf: reject invalid NAT manipulation types

As bpf_ct_set_nat_info() is not validating the NAT manipulation type a wrong value can be passed directly to nf_nat_setup_info(). This triggers the WARN_ON() at nf_nat_setup_info() and if panic_on_warn isn't set, then IPS_SRC_NAT_DONE is set without adding nat_bysource and conntrack cleanup tries to unlink an uninitialized hlist node.

Fix this by checking that NAT manipulation type is correct before calling nf_nat_setup_info(). In addition, if the WARN_ON is hit, return NF_DROP instead of continuing with the processing to avoid similar situations in the future.

Affected

• Linux >= 0fabd2aa199faeb8754aee94658f2c48ccb2c8c3 < ea777dc90ab37e64fa4b92f6fcf3b5edcef5e058
• Linux >= 0fabd2aa199faeb8754aee94658f2c48ccb2c8c3 < f6143ae109df56d51d5536e813deb19eee7a6205
• Linux >= 0fabd2aa199faeb8754aee94658f2c48ccb2c8c3 < 58108f05b0502448f6bb612ee2eccc63bd6449cb
• Linux >= 0fabd2aa199faeb8754aee94658f2c48ccb2c8c3 < 16d464013ec2267b00a83f4bfbb97b3ecc63bfa7
• Linux 6.1

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.