{"id":"CVE-2026-98694","state":"PUBLISHED","title":"thunderbolt: Fix KASAN reported use-after-free when request is canceled","description":"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  <TASK>\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  </TASK>\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.","publishedAt":"2026-10-18T15:46:18.654Z","updatedAt":"2026-10-30T12:38:46.335Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"94358146389d985b809898cc23b1030ff240a25d","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"9594550e95bcc362027b7ad5f0d5665110f8a7d8","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"0dc4296ac0910d3a43d9e105226ace463e475304","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"b70b9c41f240c42bf6e728034537c0fe60c16ef4","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"71b3c517e02af2c46ad58d4b3706b7c3cb24936d","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"f18faa3d3b810d60a3005ae1b1d1866faa67d343","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"08287212b622039212c972806f896f078dfd28e2","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"a02188ddc24b7872f0c5e0c5873f827318717803","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/ctl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/ctl.c"]}],"references":["https://git.kernel.org/stable/c/94358146389d985b809898cc23b1030ff240a25d","https://git.kernel.org/stable/c/9594550e95bcc362027b7ad5f0d5665110f8a7d8","https://git.kernel.org/stable/c/0dc4296ac0910d3a43d9e105226ace463e475304","https://git.kernel.org/stable/c/b70b9c41f240c42bf6e728034537c0fe60c16ef4","https://git.kernel.org/stable/c/71b3c517e02af2c46ad58d4b3706b7c3cb24936d","https://git.kernel.org/stable/c/f18faa3d3b810d60a3005ae1b1d1866faa67d343","https://git.kernel.org/stable/c/08287212b622039212c972806f896f078dfd28e2","https://git.kernel.org/stable/c/a02188ddc24b7872f0c5e0c5873f827318717803"],"weaknesses":[],"ingestedAt":"2026-10-30T12:58:04.520Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98694.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98694","state":"PUBLISHED","datePublished":"2026-10-18T15:46:18.654Z","dateUpdated":"2026-10-30T12:38:46.335Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.364Z"},"containers":{"cna":{"title":"thunderbolt: Fix KASAN reported use-after-free when request is canceled","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  <TASK>\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  </TASK>\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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"94358146389d985b809898cc23b1030ff240a25d","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"9594550e95bcc362027b7ad5f0d5665110f8a7d8","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"0dc4296ac0910d3a43d9e105226ace463e475304","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"b70b9c41f240c42bf6e728034537c0fe60c16ef4","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"71b3c517e02af2c46ad58d4b3706b7c3cb24936d","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"f18faa3d3b810d60a3005ae1b1d1866faa67d343","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"08287212b622039212c972806f896f078dfd28e2","versionType":"git"},{"version":"d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1","status":"affected","lessThan":"a02188ddc24b7872f0c5e0c5873f827318717803","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/ctl.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/ctl.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/94358146389d985b809898cc23b1030ff240a25d"},{"url":"https://git.kernel.org/stable/c/9594550e95bcc362027b7ad5f0d5665110f8a7d8"},{"url":"https://git.kernel.org/stable/c/0dc4296ac0910d3a43d9e105226ace463e475304"},{"url":"https://git.kernel.org/stable/c/b70b9c41f240c42bf6e728034537c0fe60c16ef4"},{"url":"https://git.kernel.org/stable/c/71b3c517e02af2c46ad58d4b3706b7c3cb24936d"},{"url":"https://git.kernel.org/stable/c/f18faa3d3b810d60a3005ae1b1d1866faa67d343"},{"url":"https://git.kernel.org/stable/c/08287212b622039212c972806f896f078dfd28e2"},{"url":"https://git.kernel.org/stable/c/a02188ddc24b7872f0c5e0c5873f827318717803"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:38:46.335Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}