{"cve":"CVE-2026-43054","nvd":{"published":"2026-05-01T15:16:51.910","modified":"2026-06-17T10:48:50.743","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: target: tcm_loop: Drain commands in target_reset handler\n\ntcm_loop_target_reset() violates the SCSI EH contract: it returns SUCCESS\nwithout draining any in-flight commands.  The SCSI EH documentation\n(scsi_eh.rst) requires that when a reset handler returns SUCCESS the driver\nhas made lower layers \"forget about timed out scmds\" and is ready for new\ncommands.  Every other SCSI LLD (virtio_scsi, mpt3sas, ipr, scsi_debug,\nmpi3mr) enforces this by draining or completing outstanding commands before\nreturning SUCCESS.\n\nBecause tcm_loop_target_reset() doesn't drain, the SCSI EH reuses in-flight\nscsi_cmnd structures for recovery commands (e.g. TUR) while the target core\nstill has async completion work queued for the old se_cmd.  The memset in\nqueuecommand zeroes se_lun and lun_ref_active, causing\ntransport_lun_remove_cmd() to skip its percpu_ref_put().  The leaked LUN\nreference prevents transport_clear_lun_ref() from completing, hanging\nconfigfs LUN unlink forever in D-state:\n\n  INFO: task rm:264 blocked for more than 122 seconds.\n  rm              D    0   264    258 0x00004000\n  Call Trace:\n   __schedule+0x3d0/0x8e0\n   schedule+0x36/0xf0\n   transport_clear_lun_ref+0x78/0x90 [target_core_mod]\n   core_tpg_remove_lun+0x28/0xb0 [target_core_mod]\n   target_fabric_port_unlink+0x50/0x60 [target_core_mod]\n   configfs_unlink+0x156/0x1f0 [configfs]\n   vfs_unlink+0x109/0x290\n   do_unlinkat+0x1d5/0x2d0\n\nFix this by making tcm_loop_target_reset() actually drain commands:\n\n 1. Issue TMR_LUN_RESET via tcm_loop_issue_tmr() to drain all commands that\n    the target core knows about (those not yet CMD_T_COMPLETE).\n\n 2. Use blk_mq_tagset_busy_iter() to iterate all started requests and\n    flush_work() on each se_cmd — this drains any deferred completion work\n    for commands that already had CMD_T_COMPLETE set before the TMR (which\n    the TMR skips via __target_check_io_state()).  This is the same pattern\n    used by mpi3mr, scsi_debug, and libsas to drain outstanding commands\n    during reset.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-772"],"references":["https://git.kernel.org/stable/c/05ac3754467363558a0a54ae4bb7c89b2c9574cf","https://git.kernel.org/stable/c/103f79e4949513247d763c6e7f3cbbf62017afdf","https://git.kernel.org/stable/c/1333eee56cdf3f0cf67c6ab4114c2c9e0a952026","https://git.kernel.org/stable/c/15f5241d5a52364a7e7867b49128b0442dbcad9d","https://git.kernel.org/stable/c/757c43c692294cdfad31390accc0e90429b2ef8a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:33:09.003606135+00:00"},"epss":{"cve":"CVE-2026-43054","score":0.00114,"percentile":0.01479,"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."]}