scsi: target: tcm_loop: Drain commands in target_reset handler
Summary
| CVE | CVE-2026-43054 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-01 15:16:51 UTC |
| Updated | 2026-05-01 15:24:14 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
scsi: target: tcm_loop: Drain commands in target_reset handler
tcm_loop_target_reset() violates the SCSI EH contract: it returns SUCCESS
without draining any in-flight commands. The SCSI EH documentation
(scsi_eh.rst) requires that when a reset handler returns SUCCESS the driver
has made lower layers "forget about timed out scmds" and is ready for new
commands. Every other SCSI LLD (virtio_scsi, mpt3sas, ipr, scsi_debug,
mpi3mr) enforces this by draining or completing outstanding commands before
returning SUCCESS.
Because tcm_loop_target_reset() doesn't drain, the SCSI EH reuses in-flight
scsi_cmnd structures for recovery commands (e.g. TUR) while the target core
still has async completion work queued for the old se_cmd. The memset in
queuecommand zeroes se_lun and lun_ref_active, causing
transport_lun_remove_cmd() to skip its percpu_ref_put(). The leaked LUN
reference prevents transport_clear_lun_ref() from completing, hanging
configfs LUN unlink forever in D-state:
INFO: task rm:264 blocked for more than 122 seconds.
rm D 0 264 258 0x00004000
Call Trace:
__schedule+0x3d0/0x8e0
schedule+0x36/0xf0
transport_clear_lun_ref+0x78/0x90 [target_core_mod]
core_tpg_remove_lun+0x28/0xb0 [target_core_mod]
target_fabric_port_unlink+0x50/0x60 [target_core_mod]
configfs_unlink+0x156/0x1f0 [configfs]
vfs_unlink+0x109/0x290
do_unlinkat+0x1d5/0x2d0
Fix this by making tcm_loop_target_reset() actually drain commands:
1. Issue TMR_LUN_RESET via tcm_loop_issue_tmr() to drain all commands that
the target core knows about (those not yet CMD_T_COMPLETE).
2. Use blk_mq_tagset_busy_iter() to iterate all started requests and
flush_work() on each se_cmd — this drains any deferred completion work
for commands that already had CMD_T_COMPLETE set before the TMR (which
the TMR skips via __target_check_io_state()). This is the same pattern
used by mpi3mr, scsi_debug, and libsas to drain outstanding commands
during reset. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 757c43c692294cdfad31390accc0e90429b2ef8a git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 103f79e4949513247d763c6e7f3cbbf62017afdf git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 15f5241d5a52364a7e7867b49128b0442dbcad9d git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 7cbd69aaa507b1245240a28022bf5da0f07c68d9 git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 a836054ea81014117ec6b73529a21626a9e1f829 git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 05ac3754467363558a0a54ae4bb7c89b2c9574cf git |
Not specified |
| CNA |
Linux |
Linux |
affected e0eb5d38b732b011cd9ed5b1bf9f59b83c2500d3 1333eee56cdf3f0cf67c6ab4114c2c9e0a952026 git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.13 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.13 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.203 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.168 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.134 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.81 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.22 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.19.12 6.19.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.0 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/1333eee56cdf3f0cf67c6ab4114c2c9e0a952026 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/05ac3754467363558a0a54ae4bb7c89b2c9574cf |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/15f5241d5a52364a7e7867b49128b0442dbcad9d |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7cbd69aaa507b1245240a28022bf5da0f07c68d9 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/a836054ea81014117ec6b73529a21626a9e1f829 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/103f79e4949513247d763c6e7f3cbbf62017afdf |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/757c43c692294cdfad31390accc0e90429b2ef8a |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.