{"cve":"CVE-2021-47549","nvd":{"published":"2024-05-24T15:15:19.773","modified":"2026-06-17T04:17:44.597","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsata_fsl: fix UAF in sata_fsl_port_stop when rmmod sata_fsl\n\nWhen the `rmmod sata_fsl.ko` command is executed in the PPC64 GNU/Linux,\na bug is reported:\n ==================================================================\n BUG: Unable to handle kernel data access on read at 0x80000800805b502c\n Oops: Kernel access of bad area, sig: 11 [#1]\n NIP [c0000000000388a4] .ioread32+0x4/0x20\n LR [80000000000c6034] .sata_fsl_port_stop+0x44/0xe0 [sata_fsl]\n Call Trace:\n  .free_irq+0x1c/0x4e0 (unreliable)\n  .ata_host_stop+0x74/0xd0 [libata]\n  .release_nodes+0x330/0x3f0\n  .device_release_driver_internal+0x178/0x2c0\n  .driver_detach+0x64/0xd0\n  .bus_remove_driver+0x70/0xf0\n  .driver_unregister+0x38/0x80\n  .platform_driver_unregister+0x14/0x30\n  .fsl_sata_driver_exit+0x18/0xa20 [sata_fsl]\n  .__se_sys_delete_module+0x1ec/0x2d0\n  .system_call_exception+0xfc/0x1f0\n  system_call_common+0xf8/0x200\n ==================================================================\n\nThe triggering of the BUG is shown in the following stack:\n\ndriver_detach\n  device_release_driver_internal\n    __device_release_driver\n      drv->remove(dev) --> platform_drv_remove/platform_remove\n        drv->remove(dev) --> sata_fsl_remove\n          iounmap(host_priv->hcr_base);\t\t\t<---- unmap\n          kfree(host_priv);                             <---- free\n      devres_release_all\n        release_nodes\n          dr->node.release(dev, dr->data) --> ata_host_stop\n            ap->ops->port_stop(ap) --> sata_fsl_port_stop\n                ioread32(hcr_base + HCONTROL)           <---- UAF\n            host->ops->host_stop(host)\n\nThe iounmap(host_priv->hcr_base) and kfree(host_priv) functions should\nnot be executed in drv->remove. These functions should be executed in\nhost_stop after port_stop. Therefore, we move these functions to the\nnew function sata_fsl_host_stop and bind the new function to host_stop.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/0769449b0a5eabc3545337217ae690e46673e73a","https://git.kernel.org/stable/c/325ea49fc43cbc03a5e1e37de8f0ca6357ced4b1","https://git.kernel.org/stable/c/4a46b2f5dce02539e88a300800812bd24a45e097","https://git.kernel.org/stable/c/6c8ad7e8cf29eb55836e7a0215f967746ab2b504","https://git.kernel.org/stable/c/77393806c76b6b44f1c44bd957788c8bd9152c45"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47549","score":0.00235,"percentile":0.14503,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}