CVE-2026-98725: nvmet-auth: fix out-of-bounds write in nvmet_auth_challenge()
In the Linux kernel, the following vulnerability has been resolved:
nvmet-auth: fix out-of-bounds write in nvmetauthchallenge()
nvmetauthchallenge() receives its output buffer as a void pointer. sizeof(d) therefore evaluates to one with GCC and undercounts the fixed challenge header by 15 bytes. A short AUTHRECEIVE buffer can pass the check before the challenge is copied past the end of its allocation.
Use the typed challenge pointer when calculating the response size.
BUG: KASAN: slab-out-of-bounds in nvmetexecuteauthreceive (drivers/nvme/target/fabrics-cmd-auth.c:442 drivers/nvme/target/fabrics-cmd-auth.c:569) Write of size 32 by task kworker/1:1H/64 Workqueue: nvmettcpwq nvmettcpiowork Call Trace: nvmetexecuteauthreceive (drivers/nvme/target/fabrics-cmd-auth.c:442 drivers/nvme/target/fabrics-cmd-auth.c:569) nvmettcptryrecvpdu (drivers/nvme/target/tcp.c:1119 drivers/nvme/target/tcp.c:1243) nvmettcpiowork (drivers/nvme/target/tcp.c:1350 drivers/nvme/target/tcp.c:1382 drivers/nvme/target/tcp.c:1445) processonework (kernel/workqueue.c:3322) workerthread (kernel/workqueue.c:3405 kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) retfromfork (arch/x86/kernel/process.c:158) retfromforkasm (arch/x86/entry/entry64.S:245) The buggy address is located 16 bytes inside of allocated 33-byte region [ffff888000554e80, ffff888000554ea1) Kernel panic - not syncing: KASAN: paniconwarn set ...
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.113-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 7.2.10-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.160 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.113 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.18.56 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 7.2.10 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Compensating control
In nvmet_auth_challenge(), use the typed challenge pointer when calculating the response size so the fixed challenge header is counted correctly and short AUTH_RECEIVE buffers cannot pass validation before the challenge is copied.
Event History
Frequently Asked Questions
Which systems are exposed to this flaw?
Systems running the Linux kernel with the NVMe target authentication path in use are exposed, specifically when processing NVMe-oF TCP AUTH_RECEIVE requests. The reported fault occurs in the nvmet TCP workqueue.
What does an attacker need to trigger the out-of-bounds write?
An attacker needs to send a short AUTH_RECEIVE buffer to the NVMe target authentication handling path. The undersized buffer can pass the incorrect size check before challenge data is copied beyond its allocation.
How can I determine whether the issue is being triggered?
Kernel memory-safety diagnostics may report a KASAN slab-out-of-bounds write in nvmet_execute_auth_receive. The supplied trace shows the write occurring through nvmet_tcp_try_recv_pdu and nvmet_tcp_io_work.