tipc: fix out-of-bounds read in broadcast Gap ACK blocks
In the Linux kernel, the following vulnerability has been resolved: tipc: fix out-of-bounds read in broadcast Gap ACK blocks A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its data area. tipc_get_gap_ack_blks() only verifies that the record's len field is self-consistent with its ugack_cnt/bgack_cnt counts (sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check that the record actually fits in the message data area, msg_data_sz(). The unicast caller tipc_link_proto_rcv() bounds it ("if (glen > dlen) break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the returned size, so tipc_link_advance_transmq() copies the record off the receive skb with an attacker-controlled count: this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt), GFP_ATOMIC); A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its data area is short, carrying a Gap ACK record with len = 0x400, bgack_cnt = 0xff and ugack_cnt = 0. len then equals struct_size(p, gacks, 255), so the consistency check passes and ga is non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out of the much smaller skb: BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60 Read of size 1024 at addr ffff0000c7030d38 by task poc864/69 Call trace: kmemdup_noprof+0x48/0x60 tipc_link_advance_transmq+0x86c/0xb80 tipc_link_bc_ack_rcv+0x19c/0x1e0 tipc_bcast_sync_rcv+0x1c4/0x2c4 tipc_rcv
CVE-2026-64450
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-2026-64450
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": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "055663d21dc4336f67933ab26bef3c5934be6324",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "016f5995c37a5a2c45198308f830f244517d70b7",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "74b45af86a767594ba52330cd440ea84e24d700d",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "9a51115fcdc78687c8852bf93a1db3951dbb223b",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "a21ed5064217cc33726da6c7ef1a520eba43aea1",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "2de42e268174766cb2e2b90721afdfdff70e0d8d",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "f333b6851bdf326fd2134133272dbbed0c94d921",
"versionType": "git"
},
{
"status": "affected",
"version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa",
"lessThan": "2b66974a1b6134a4bbc3bfed181f7418f688eb54",
"versionType": "git"
}
],
"programFiles": [
"net/tipc/bcast.c",
"net/tipc/bcast.h",
"net/tipc/node.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.8",
"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": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/tipc/bcast.c",
"net/tipc/bcast.h",
"net/tipc/node.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64450
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #41052 · Revision 1
- Added to Heist Feed
- Publisher date