FKIE_CVE-2026-98694
Vulnerability from fkie_nvd - Published: 2026-10-18 16:17 - Updated: 2026-10-30 13:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Fix KASAN reported use-after-free when request is canceled
Alan reported that when doing stress testing sometimes KASAN notices
use-after-free during control channel operation (stripped down keeping
the relevant parts):
BUG: KASAN: slab-use-after-free in tb_cfg_request_sync+0x240/0x250 [thunderbolt]
Read of size 24 at addr ffff88811067f290 by task kworker/u40:2/1760
<TASK>
tb_cfg_request_sync+0x240/0x250 [thunderbolt]
tb_cfg_read_raw+0x367/0x510 [thunderbolt]
tb_cfg_read+0xec/0x240 [thunderbolt]
tb_port_get_link_generation+0x258/0x420 [thunderbolt]
tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]
tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]
tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]
tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]
tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]
process_one_work+0x675/0x1230
worker_thread+0x5e6/0xf70
kthread+0x365/0x470
ret_from_fork+0x54d/0x710
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1760:
__kmalloc_cache_noprof+0x1ee/0x550
tb_cfg_read_raw+0x1d3/0x510 [thunderbolt]
tb_cfg_read+0xec/0x240 [thunderbolt]
tb_port_get_link_generation+0x258/0x420 [thunderbolt]
tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]
tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]
tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]
tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]
tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]
process_one_work+0x675/0x1230
worker_thread+0x5e6/0xf70
kthread+0x365/0x470
ret_from_fork+0x54d/0x710
ret_from_fork_asm+0x1a/0x30
Freed by task 926:
kfree+0x18f/0x4a0
tb_cfg_request_put+0xb7/0xe0 [thunderbolt]
tb_cfg_request_work+0x82/0x120 [thunderbolt]
process_one_work+0x675/0x1230
worker_thread+0x5e6/0xf70
kthread+0x365/0x470
ret_from_fork+0x54d/0x710
ret_from_fork_asm+0x1a/0x30
Second to last potentially related work creation:
__queue_work+0x575/0xd00
queue_work_on+0x77/0x80
tb_cfg_request_cancel+0xc7/0x260 [thunderbolt]
tb_cfg_request_sync+0x1f6/0x250 [thunderbolt]
tb_cfg_read_raw+0x367/0x510 [thunderbolt]
tb_cfg_read+0xec/0x240 [thunderbolt]
tb_port_get_link_generation+0x258/0x420 [thunderbolt]
tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]
tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]
tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]
tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]
tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]
process_one_work+0x675/0x1230
worker_thread+0x5e6/0xf70
kthread+0x365/0x470
ret_from_fork+0x54d/0x710
ret_from_fork_asm+0x1a/0x30
The last stack trace is helpful because it shows that we are cancelling
a request and looking at tb_cfg_request_cancel() what might happen is
that tb_cfg_request_work() completes right before tb_cfg_request_cancel()
starts and because of this it will call schedule_work() queueing the
same work to run again. However, it is already removed from the
request_queue and reference count is dropped so when
tb_cfg_request_work() triggers again it will access memory that is
already released.
Fix this so that we first make sure a cancelled request is not handed
away from tb_cfg_request_find() or scheduled to run. Then instead of
relying on the worker to clean up the request we will do it in
tb_cfg_request_cancel() after the work is canceled from running. Make
tb_cfg_request_dequeue() release the request only if it was actually
removed from the queue.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/thunderbolt/ctl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "94358146389d985b809898cc23b1030ff240a25d",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "9594550e95bcc362027b7ad5f0d5665110f8a7d8",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "0dc4296ac0910d3a43d9e105226ace463e475304",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "b70b9c41f240c42bf6e728034537c0fe60c16ef4",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "71b3c517e02af2c46ad58d4b3706b7c3cb24936d",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "f18faa3d3b810d60a3005ae1b1d1866faa67d343",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "08287212b622039212c972806f896f078dfd28e2",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
},
{
"lessThan": "a02188ddc24b7872f0c5e0c5873f827318717803",
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/thunderbolt/ctl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.13"
},
{
"lessThan": "4.13",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.273",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.224",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.191",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"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\nthunderbolt: Fix KASAN reported use-after-free when request is canceled\n\nAlan reported that when doing stress testing sometimes KASAN notices\nuse-after-free during control channel operation (stripped down keeping\nthe relevant parts):\n\n BUG: KASAN: slab-use-after-free in tb_cfg_request_sync+0x240/0x250 [thunderbolt]\n Read of size 24 at addr ffff88811067f290 by task kworker/u40:2/1760\n \u003cTASK\u003e\n tb_cfg_request_sync+0x240/0x250 [thunderbolt]\n tb_cfg_read_raw+0x367/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n \u003c/TASK\u003e\n\n Allocated by task 1760:\n __kmalloc_cache_noprof+0x1ee/0x550\n tb_cfg_read_raw+0x1d3/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\n Freed by task 926:\n kfree+0x18f/0x4a0\n tb_cfg_request_put+0xb7/0xe0 [thunderbolt]\n tb_cfg_request_work+0x82/0x120 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\n Second to last potentially related work creation:\n __queue_work+0x575/0xd00\n queue_work_on+0x77/0x80\n tb_cfg_request_cancel+0xc7/0x260 [thunderbolt]\n tb_cfg_request_sync+0x1f6/0x250 [thunderbolt]\n tb_cfg_read_raw+0x367/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\nThe last stack trace is helpful because it shows that we are cancelling\na request and looking at tb_cfg_request_cancel() what might happen is\nthat tb_cfg_request_work() completes right before tb_cfg_request_cancel()\nstarts and because of this it will call schedule_work() queueing the\nsame work to run again. However, it is already removed from the\nrequest_queue and reference count is dropped so when\ntb_cfg_request_work() triggers again it will access memory that is\nalready released.\n\nFix this so that we first make sure a cancelled request is not handed\naway from tb_cfg_request_find() or scheduled to run. Then instead of\nrelying on the worker to clean up the request we will do it in\ntb_cfg_request_cancel() after the work is canceled from running. Make\ntb_cfg_request_dequeue() release the request only if it was actually\nremoved from the queue."
}
],
"id": "CVE-2026-98694",
"lastModified": "2026-10-30T13:21:18.383",
"metrics": {},
"published": "2026-10-18T16:17:22.830",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/08287212b622039212c972806f896f078dfd28e2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0dc4296ac0910d3a43d9e105226ace463e475304"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/71b3c517e02af2c46ad58d4b3706b7c3cb24936d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/94358146389d985b809898cc23b1030ff240a25d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9594550e95bcc362027b7ad5f0d5665110f8a7d8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a02188ddc24b7872f0c5e0c5873f827318717803"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b70b9c41f240c42bf6e728034537c0fe60c16ef4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f18faa3d3b810d60a3005ae1b1d1866faa67d343"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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