netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp() sip_help_tcp() stores the size change of each NAT-rewritten SIP message in s16 diff and accumulates it in s16 tdiff, but a single message can grow by more than S16_MAX while the packet stays under the 65535 enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long Contact list expands the message by tens of kilobytes. diff then wraps, and "datalen = datalen + diff - msglen" yields a huge unsigned datalen, so the next iteration's ct_sip_get_header() reads past the linearized skb tail. Widen diff, tdiff and the seq_adjust hook to s32. Both are bounded by the 65535 byte packet limit, and the seqadj core is already s32 (nf_ct_seqadj_set() takes s32), so no previously accepted input is rejected. BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25 ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694) nf_confirm (net/netfilter/nf_conntrack_proto.c:183) nf_hook_slow (net/netfilter/core.c:619) ip6_output (net/ipv6/ip6_output.c:246) ip6_forward (net/ipv6/ip6_output.c:690) ipv6_rcv (net/ipv6/ip6_input.c:351) __netif_receive_skb_one_core (net/core/dev.c:6212) process_backlog (net/core/dev.c:6676) __napi_poll (net/core/dev.c:7735) net_rx_action (net/core/dev.c:7955) handle_softi
CVE-2026-74569
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-74569
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "32d4abc8923b0d4046fd63ad6e4917872e44eb6d",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "63eea41759fd682229c14e0a2205802b46d106f3",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "c97621a110e386b2dd69e276eb699e1d3cec581d",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "f74554e67ccf04d1fa71069e8c9afa2717e40716",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64",
"versionType": "git"
},
{
"status": "affected",
"version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
"lessThan": "db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5",
"versionType": "git"
}
],
"programFiles": [
"include/linux/netfilter/nf_conntrack_sip.h",
"net/netfilter/nf_conntrack_sip.c",
"net/netfilter/nf_nat_sip.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.34"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.34",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.151",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/netfilter/nf_conntrack_sip.h",
"net/netfilter/nf_conntrack_sip.c",
"net/netfilter/nf_nat_sip.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74569
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #33210 · Revision 1
- Added to Heist Feed
- Publisher date