FKIE_CVE-2026-64545
Vulnerability from fkie_nvd - Published: 2026-07-27 21:17 - Updated: 2026-07-30 06:25
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net, bpf: check master for NULL in xdp_master_redirect()
xdp_master_redirect() dereferences the result of
netdev_master_upper_dev_get_rcu() without a NULL check, but that helper
returns NULL when the receiving device has no upper-master adjacency.
The reach guard only checks netif_is_bond_slave(). On bond slave release
bond_upper_dev_unlink() drops the upper-master adjacency before clearing
IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window
still passes netif_is_bond_slave() while master is already NULL, and
faults on master->flags at offset 0xb0:
BUG: kernel NULL pointer dereference, address: 00000000000000b0
RIP: 0010:xdp_master_redirect (net/core/filter.c:4432)
Call Trace:
xdp_master_redirect (net/core/filter.c:4432)
bpf_prog_run_generic_xdp (include/net/xdp.h:700)
do_xdp_generic (net/core/dev.c:5608)
__netif_receive_skb_one_core (net/core/dev.c:6204)
process_backlog (net/core/dev.c:6319)
__napi_poll (net/core/dev.c:7729)
net_rx_action (net/core/dev.c:7792)
handle_softirqs (kernel/softirq.c:622)
__dev_queue_xmit (include/linux/bottom_half.h:33)
packet_sendmsg (net/packet/af_packet.c:3082)
__sys_sendto (net/socket.c:2252)
Kernel panic - not syncing: Fatal exception in interrupt
The missing check dates back to the original code; commit 1921f91298d1
("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master")
later added the master->flags read where the fault now lands but kept the
unconditional deref. Check master for NULL before use; a NULL master is
treated the same as one that is not up.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/core/filter.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c99ca049e910d61ddbd28cc2c47242f2bfbb4970",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "e2a56441233131fe18a76001de347ecda217e40c",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "3876318ea54e83eb70982b8280a3c5e4e32269bf",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "4edbcacca09f92b85d3951b6add11894b20a84bc",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "03b743586a2469744e96e9c1015096d07240935d",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "89c103d702b25ceb2d097faf854deb47b53b17ff",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
},
{
"lessThan": "e82d8cc4321c373dc46e741cd2dfdaa7921fddb7",
"status": "affected",
"version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/core/filter.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"lessThan": "5.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet, bpf: check master for NULL in xdp_master_redirect()\n\nxdp_master_redirect() dereferences the result of\nnetdev_master_upper_dev_get_rcu() without a NULL check, but that helper\nreturns NULL when the receiving device has no upper-master adjacency.\n\nThe reach guard only checks netif_is_bond_slave(). On bond slave release\nbond_upper_dev_unlink() drops the upper-master adjacency before clearing\nIFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window\nstill passes netif_is_bond_slave() while master is already NULL, and\nfaults on master-\u003eflags at offset 0xb0:\n\n BUG: kernel NULL pointer dereference, address: 00000000000000b0\n RIP: 0010:xdp_master_redirect (net/core/filter.c:4432)\n Call Trace:\n xdp_master_redirect (net/core/filter.c:4432)\n bpf_prog_run_generic_xdp (include/net/xdp.h:700)\n do_xdp_generic (net/core/dev.c:5608)\n __netif_receive_skb_one_core (net/core/dev.c:6204)\n process_backlog (net/core/dev.c:6319)\n __napi_poll (net/core/dev.c:7729)\n net_rx_action (net/core/dev.c:7792)\n handle_softirqs (kernel/softirq.c:622)\n __dev_queue_xmit (include/linux/bottom_half.h:33)\n packet_sendmsg (net/packet/af_packet.c:3082)\n __sys_sendto (net/socket.c:2252)\n Kernel panic - not syncing: Fatal exception in interrupt\n\nThe missing check dates back to the original code; commit 1921f91298d1\n(\"net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master\")\nlater added the master-\u003eflags read where the fault now lands but kept the\nunconditional deref. Check master for NULL before use; a NULL master is\ntreated the same as one that is not up."
}
],
"id": "CVE-2026-64545",
"lastModified": "2026-07-30T06:25:58.200",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-27T21:17:07.130",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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