| { |
| "containers": { |
| "cna": { |
| "providerMetadata": { |
| "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" |
| }, |
| "descriptions": [ |
| { |
| "lang": "en", |
| "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix memory leak in fib6_rule_suppress\n\nThe kernel leaks memory when a `fib` rule is present in IPv6 nftables\nfirewall rules and a suppress_prefix rule is present in the IPv6 routing\nrules (used by certain tools such as wg-quick). In such scenarios, every\nincoming packet will leak an allocation in `ip6_dst_cache` slab cache.\n\nAfter some hours of `bpftrace`-ing and source code reading, I tracked\ndown the issue to ca7a03c41753 (\"ipv6: do not free rt if\nFIB_LOOKUP_NOREF is set on suppress rule\").\n\nThe problem with that change is that the generic `args->flags` always have\n`FIB_LOOKUP_NOREF` set[1][2] but the IPv6-specific flag\n`RT6_LOOKUP_F_DST_NOREF` might not be, leading to `fib6_rule_suppress` not\ndecreasing the refcount when needed.\n\nHow to reproduce:\n - Add the following nftables rule to a prerouting chain:\n meta nfproto ipv6 fib saddr . mark . iif oif missing drop\n This can be done with:\n sudo nft create table inet test\n sudo nft create chain inet test test_chain '{ type filter hook prerouting priority filter + 10; policy accept; }'\n sudo nft add rule inet test test_chain meta nfproto ipv6 fib saddr . mark . iif oif missing drop\n - Run:\n sudo ip -6 rule add table main suppress_prefixlength 0\n - Watch `sudo slabtop -o | grep ip6_dst_cache` to see memory usage increase\n with every incoming ipv6 packet.\n\nThis patch exposes the protocol-specific flags to the protocol\nspecific `suppress` function, and check the protocol-specific `flags`\nargument for RT6_LOOKUP_F_DST_NOREF instead of the generic\nFIB_LOOKUP_NOREF when decreasing the refcount, like this.\n\n[1]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L71\n[2]: https://github.com/torvalds/linux/blob/ca7a03c4175366a92cee0ccc4fec0038c3266e26/net/ipv6/fib6_rules.c#L99" |
| } |
| ], |
| "affected": [ |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "unaffected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "include/net/fib_rules.h", |
| "net/core/fib_rules.c", |
| "net/ipv4/fib_rules.c", |
| "net/ipv6/fib6_rules.c" |
| ], |
| "versions": [ |
| { |
| "version": "ca7a03c4175366a92cee0ccc4fec0038c3266e26", |
| "lessThan": "ee38eb8cf9a7323884c2b8e0adbbeb2192d31e29", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "ca7a03c4175366a92cee0ccc4fec0038c3266e26", |
| "lessThan": "209d35ee34e25f9668c404350a1c86d914c54ffa", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "ca7a03c4175366a92cee0ccc4fec0038c3266e26", |
| "lessThan": "8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "ca7a03c4175366a92cee0ccc4fec0038c3266e26", |
| "lessThan": "cdef485217d30382f3bf6448c54b4401648fe3f1", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "d37c966752043733eb847dd897d6e3405084c559", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "ecc265624956ea784cb2bd2b31a95bd54c4f5f13", |
| "status": "affected", |
| "versionType": "git" |
| } |
| ] |
| }, |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "affected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "include/net/fib_rules.h", |
| "net/core/fib_rules.c", |
| "net/ipv4/fib_rules.c", |
| "net/ipv6/fib6_rules.c" |
| ], |
| "versions": [ |
| { |
| "version": "5.4", |
| "status": "affected" |
| }, |
| { |
| "version": "0", |
| "lessThan": "5.4", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.4.164", |
| "lessThanOrEqual": "5.4.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.10.84", |
| "lessThanOrEqual": "5.10.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.15.7", |
| "lessThanOrEqual": "5.15.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.16", |
| "lessThanOrEqual": "*", |
| "status": "unaffected", |
| "versionType": "original_commit_for_fix" |
| } |
| ] |
| } |
| ], |
| "cpeApplicability": [ |
| { |
| "nodes": [ |
| { |
| "operator": "OR", |
| "negate": false, |
| "cpeMatch": [ |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.4", |
| "versionEndExcluding": "5.4.164" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.4", |
| "versionEndExcluding": "5.10.84" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.4", |
| "versionEndExcluding": "5.15.7" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.4", |
| "versionEndExcluding": "5.16" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.2.19" |
| }, |
| { |
| "vulnerable": true, |
| "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", |
| "versionStartIncluding": "5.3.4" |
| } |
| ] |
| } |
| ] |
| } |
| ], |
| "references": [ |
| { |
| "url": "https://git.kernel.org/stable/c/ee38eb8cf9a7323884c2b8e0adbbeb2192d31e29" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/209d35ee34e25f9668c404350a1c86d914c54ffa" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/8ef8a76a340ebdb2c2eea3f6fb0ebbed09a16383" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/cdef485217d30382f3bf6448c54b4401648fe3f1" |
| } |
| ], |
| "title": "ipv6: fix memory leak in fib6_rule_suppress", |
| "x_generator": { |
| "engine": "bippy-1.2.0" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2021-47546", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
