netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() br_ip6_fragment() gets prevhdr, a pointer into the skb head, from ip6_find_1stfragopt(), then calls skb_checksum_help(). For a cloned skb skb_checksum_help() reallocates the head via pskb_expand_head(), leaving prevhdr dangling. It is later dereferenced in ip6_frag_next(), causing a use-after-free write. Save prevhdr's offset before skb_checksum_help() and recompute it after, like commit ef0efcd3bd3f ("ipv6: Fix dangling pointer when ipv6 fragment"). BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857) Write of size 1 at addr ffff888013ff5016 by task exploit/141 Call Trace: ... kasan_report (mm/kasan/report.c:595) ip6_frag_next (net/ipv6/ip6_output.c:857) br_ip6_fragment (net/ipv6/netfilter.c:212) nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407) nf_hook_slow (net/netfilter/core.c:619) br_forward_finish (net/bridge/br_forward.c:66) __br_forward (net/bridge/br_forward.c:115) maybe_deliver (net/bridge/br_forward.c:191) br_flood (net/bridge/br_forward.c:245) br_handle_frame_finish (net/bridge/br_input.c:229) br_handle_frame (net/bridge/br_input.c:442) ... packet_sendmsg (net/packet/af_packet.c:3114) ... do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Kernel panic - not syncing: Fatal exception in interrupt
CVE-2026-64554
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-2026-64554
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": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "8c10778ec674b67a07ea042fcba64270f3f38a5a",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "2731efa6364e47934c96eb69e01ea131e8af8030",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "00c06ef8c018493943891a7d0ca82b71b24f3180",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "c141f69d0a0fb16964dbc293650047e69bda8af7",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "f2e6596d10783557aeb9668da2a3b4d19deb2001",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "1c4f67c89fd27c4df4c70b135c2c59627698b3c0",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "4ac981a8b7ce7aec99a52d08f8a8953e8e120067",
"versionType": "git"
},
{
"status": "affected",
"version": "764dd163ac922f8683b5bcd3007251ce7b26cd33",
"lessThan": "86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d",
"versionType": "git"
}
],
"programFiles": [
"net/ipv6/netfilter.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv6/netfilter.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64554
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41082 · Revision 1
- Added to Heist Feed
- Publisher date