{"id":"CVE-2026-43054","summary":"scsi: target: tcm_loop: Drain commands in target_reset handler","details":"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.","modified":"2026-05-18T06:00:12.440585146Z","published":"2026-05-01T14:15:47.396Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43054.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/05ac3754467363558a0a54ae4bb7c89b2c9574cf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/103f79e4949513247d763c6e7f3cbbf62017afdf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1333eee56cdf3f0cf67c6ab4114c2c9e0a952026"},{"type":"WEB","url":"https://git.kernel.org/stable/c/15f5241d5a52364a7e7867b49128b0442dbcad9d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/757c43c692294cdfad31390accc0e90429b2ef8a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7cbd69aaa507b1245240a28022bf5da0f07c68d9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a836054ea81014117ec6b73529a21626a9e1f829"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43054.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43054"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3"},{"fixed":"757c43c692294cdfad31390accc0e90429b2ef8a"},{"fixed":"103f79e4949513247d763c6e7f3cbbf62017afdf"},{"fixed":"15f5241d5a52364a7e7867b49128b0442dbcad9d"},{"fixed":"7cbd69aaa507b1245240a28022bf5da0f07c68d9"},{"fixed":"a836054ea81014117ec6b73529a21626a9e1f829"},{"fixed":"05ac3754467363558a0a54ae4bb7c89b2c9574cf"},{"fixed":"1333eee56cdf3f0cf67c6ab4114c2c9e0a952026"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43054.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.13.0"},{"fixed":"5.15.203"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.168"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.81"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43054.json"}}],"schema_version":"1.7.5"}