mlxsw: spectrum_router: Fix neighbour use-after-free
In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_router: Fix neighbour use-after-free We sometimes observe use-after-free when dereferencing a neighbour [1]. The problem seems to be that the driver stores a pointer to the neighbour, but without holding a reference on it. A reference is only taken when the neighbour is used by a nexthop. Fix by simplifying the reference counting scheme. Always take a reference when storing a neighbour pointer in a neighbour entry. Avoid taking a referencing when the neighbour is used by a nexthop as the neighbour entry associated with the nexthop already holds a reference. Tested by running the test that uncovered the problem over 300 times. Without this patch the problem was reproduced after a handful of iterations. [1] BUG: KASAN: slab-use-after-free in mlxsw_sp_neigh_entry_update+0x2d4/0x310 Read of size 8 at addr ffff88817f8e3420 by task ip/3929 CPU: 3 UID: 0 PID: 3929 Comm: ip Not tainted 6.18.0-rc4-virtme-g36b21a067510 #3 PREEMPT(full) Hardware name: Nvidia SN5600/VMOD0013, BIOS 5.13 05/31/2023 Call Trace: dump_stack_lvl+0x6f/0xa0 print_address_description.constprop.0+0x6e/0x300 print_report+0xfc/0x1fb kasan_report+0xe4/0x110 mlxsw_sp_neigh_entry_update+0x2d4/0x310 mlxsw_sp_router_rif_gone_sync+0x35f/0x510 mlxsw_sp_rif_destroy+0x1ea/0x730 mlxsw_sp_inetaddr_port_vlan_event+0xa1/0x1b0 __mlxsw_sp_inetaddr_lag_event+0xcc/0x130 __mlxsw_sp_inetaddr_event+0xf5/0x3c0 mlxsw_sp_router_netdevice_event+0x1015/0x158
CVE-2025-68801
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-2025-68801
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": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "a2dfe6758fc63e542105bee8b17a3a7485684db0",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "9e0a0d9eeb0dbeba2c83fa837885b19b8b9230fc",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "c437fbfd4382412598cdda1f8e2881b523668cc2",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "4a3c569005f42ab5e5b2ad637132a33bf102cc08",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "ed8141b206bdcfd5d0b92c90832eeb77b7a60a0a",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "675c5aeadf6472672c472dc0f26401e4fcfbf254",
"versionType": "git"
},
{
"status": "affected",
"version": "6cf3c971dc84cb36579515ddb488919b9e9fb6de",
"lessThan": "8b0e69763ef948fb872a7767df4be665d18f5fd4",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.248",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.198",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.160",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.120",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.64",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.3",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-68801
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39127 · Revision 1
- Added to Heist Feed
- Publisher date