{"id":"CVE-2026-43203","state":"PUBLISHED","title":"atm: fore200e: fix use-after-free in tasklets during device removal","description":"In the Linux kernel, the following vulnerability has been resolved:\n\natm: fore200e: fix use-after-free in tasklets during device removal\n\nWhen the PCA-200E or SBA-200E adapter is being detached, the fore200e\nis deallocated. However, the tx_tasklet or rx_tasklet may still be running\nor pending, leading to use-after-free bug when the already freed fore200e\nis accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().\n\nOne of the race conditions can occur as follows:\n\nCPU 0 (cleanup)           | CPU 1 (tasklet)\nfore200e_pca_remove_one() | fore200e_interrupt()\n  fore200e_shutdown()     |   tasklet_schedule()\n    kfree(fore200e)       | fore200e_tx_tasklet()\n                          |   fore200e-> // UAF\n\nFix this by ensuring tx_tasklet or rx_tasklet is properly canceled before\nthe fore200e is released. Add tasklet_kill() in fore200e_shutdown() to\nsynchronize with any pending or running tasklets. Moreover, since\nfore200e_reset() could prevent further interrupts or data transfers,\nthe tasklet_kill() should be placed after fore200e_reset() to prevent\nthe tasklet from being rescheduled in fore200e_interrupt(). Finally,\nit only needs to do tasklet_kill() when the fore200e state is greater\nthan or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized\nin earlier states. In a word, the tasklet_kill() should be placed in\nthe FORE200E_STATE_IRQ branch within the switch...case structure.\n\nThis bug was identified through static analysis.","publishedAt":"2026-05-06T11:28:08.949Z","updatedAt":"2026-08-05T12:26:31.918Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"91f25749aaf57c47ae1e12478144e6ea8c8562f2","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"73fbc5d1a9ccb626937500bbd67136f077d8237b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"aba0b4bc09376dfc3d53c826514fe38fc8337f52","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e075ec9b08f862dade8011481058f7eb5f716c57","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"97900f512252a59f23d6ce4ab215cc88fed66e68","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5189368f10903956be05062d160b2804bf5e5016","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"8930878101cd40063888a68af73b1b0f8b6c79bc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/atm/fore200e.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/atm/fore200e.c"]}],"references":["https://git.kernel.org/stable/c/91f25749aaf57c47ae1e12478144e6ea8c8562f2","https://git.kernel.org/stable/c/73fbc5d1a9ccb626937500bbd67136f077d8237b","https://git.kernel.org/stable/c/aba0b4bc09376dfc3d53c826514fe38fc8337f52","https://git.kernel.org/stable/c/e075ec9b08f862dade8011481058f7eb5f716c57","https://git.kernel.org/stable/c/97900f512252a59f23d6ce4ab215cc88fed66e68","https://git.kernel.org/stable/c/e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d","https://git.kernel.org/stable/c/5189368f10903956be05062d160b2804bf5e5016","https://git.kernel.org/stable/c/8930878101cd40063888a68af73b1b0f8b6c79bc"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43203.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43203","state":"PUBLISHED","datePublished":"2026-05-06T11:28:08.949Z","dateUpdated":"2026-08-05T12:26:31.918Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.992Z"},"containers":{"cna":{"title":"atm: fore200e: fix use-after-free in tasklets during device removal","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\natm: fore200e: fix use-after-free in tasklets during device removal\n\nWhen the PCA-200E or SBA-200E adapter is being detached, the fore200e\nis deallocated. However, the tx_tasklet or rx_tasklet may still be running\nor pending, leading to use-after-free bug when the already freed fore200e\nis accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().\n\nOne of the race conditions can occur as follows:\n\nCPU 0 (cleanup)           | CPU 1 (tasklet)\nfore200e_pca_remove_one() | fore200e_interrupt()\n  fore200e_shutdown()     |   tasklet_schedule()\n    kfree(fore200e)       | fore200e_tx_tasklet()\n                          |   fore200e-> // UAF\n\nFix this by ensuring tx_tasklet or rx_tasklet is properly canceled before\nthe fore200e is released. Add tasklet_kill() in fore200e_shutdown() to\nsynchronize with any pending or running tasklets. Moreover, since\nfore200e_reset() could prevent further interrupts or data transfers,\nthe tasklet_kill() should be placed after fore200e_reset() to prevent\nthe tasklet from being rescheduled in fore200e_interrupt(). Finally,\nit only needs to do tasklet_kill() when the fore200e state is greater\nthan or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized\nin earlier states. In a word, the tasklet_kill() should be placed in\nthe FORE200E_STATE_IRQ branch within the switch...case structure.\n\nThis bug was identified through static analysis."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"91f25749aaf57c47ae1e12478144e6ea8c8562f2","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"73fbc5d1a9ccb626937500bbd67136f077d8237b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"aba0b4bc09376dfc3d53c826514fe38fc8337f52","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e075ec9b08f862dade8011481058f7eb5f716c57","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"97900f512252a59f23d6ce4ab215cc88fed66e68","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"5189368f10903956be05062d160b2804bf5e5016","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"8930878101cd40063888a68af73b1b0f8b6c79bc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/atm/fore200e.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/atm/fore200e.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/91f25749aaf57c47ae1e12478144e6ea8c8562f2"},{"url":"https://git.kernel.org/stable/c/73fbc5d1a9ccb626937500bbd67136f077d8237b"},{"url":"https://git.kernel.org/stable/c/aba0b4bc09376dfc3d53c826514fe38fc8337f52"},{"url":"https://git.kernel.org/stable/c/e075ec9b08f862dade8011481058f7eb5f716c57"},{"url":"https://git.kernel.org/stable/c/97900f512252a59f23d6ce4ab215cc88fed66e68"},{"url":"https://git.kernel.org/stable/c/e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d"},{"url":"https://git.kernel.org/stable/c/5189368f10903956be05062d160b2804bf5e5016"},{"url":"https://git.kernel.org/stable/c/8930878101cd40063888a68af73b1b0f8b6c79bc"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - ATM link traffic from a remote peer can cause the adapter IRQ path (`fore200e_interrupt()`) to schedule the vulnerable RX/TX tasklets. The freeing side occurs during adapter removal, but the attacker-controlled stimulus reaches the vulnerable tasklet path over the network-facing ATM device.\nAC:H - The bug requires the non-default `CONFIG_ATM_FORE200E_USE_TASKLET` configuration and a removal event overlapping a pending or running tasklet. The remote attacker can keep interrupts likely, but does not fully control the removal side.\nPR:N - A remote ATM peer does not need credentials or local privileges on the vulnerable host to generate traffic that posts adapter interrupts. Local sysfs unbind/module removal would require real root, but the highest-severity reasonable scenario uses unauthenticated remote traffic coinciding with victim-initiated removal.\nUI:R - Network traffic alone does not free `struct fore200e`; a user/admin action or physical hotplug/removal event must detach, unbind, or remove the adapter. Once removal occurs, pending tasklets can access the freed structure.\nS:U - The corruption occurs within the kernel/driver context and affects resources under the same kernel security authority. There is no VM escape, IOMMU bypass, or cross-scope boundary indicated.\nC:H - This is a use-after-free of the driver’s per-device structure, and the tasklets dereference freed pointers and queues after teardown. Per the kernel scoring guidance, UAF memory corruption is treated as enabling high confidentiality impact.\nI:H - The freed `struct fore200e` can be reallocated or corrupted before tasklet execution, creating a plausible control-flow or arbitrary-write primitive. Per the kernel scoring guidance, UAF memory corruption warrants high integrity impact.\nA:H - The tasklets dereference freed driver state after `kfree(fore200e)`, which can directly cause kernel oops, panic, or hang. Any kernel crash from this UAF is high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:26:31.918Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}