kernel/linux.git/drivers/target/target_core_pr.c, branch v6.6.150

scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE

2026-07-24T14:03:40+00:00

commit fda6a1f3c3d7047b5ce5654487649c2daa738bfc upstream. core_scsi3_emulate_pro_register_and_move() maps the PERSISTENT RESERVE OUT parameter list with transport_kmap_data_sg() and parses the destination TransportID with target_parse_pr_out_transport_id(). For an iSCSI TransportID (FORMAT CODE 01b), iscsi_parse_pr_out_transport_id() returns the ISID in iport_ptr as a raw pointer into that mapped buffer. The function then unmaps the buffer with transport_kunmap_data_sg() before dereferencing iport_ptr in strcmp(), __core_scsi3_locate_pr_reg() and core_scsi3_alloc_registration(). When the parameter list spans more than one page (PARAMETER LIST LENGTH > 4096), transport_kmap_data_sg() uses vmap() and transport_kunmap_data_sg() does vunmap(), so the kernel virtual address backing iport_ptr is torn down and every subsequent dereference is a use-after-free read of the unmapped region. Keep the parameter list mapped until iport_ptr is no longer needed: drop the early transport_kunmap_data_sg() and unmap once on the success path, right before returning. The error paths already unmap through the existing "if (buf) transport_kunmap_data_sg(cmd)" at the out: label, which now runs on every post-map error exit because buf is no longer cleared early. Only reads of the mapping happen while spinlocks are held; the map and unmap calls remain outside any lock. The sibling caller core_scsi3_decode_spec_i_port() already uses the buffer before unmapping it and is left unchanged. Fixes: 4949314c7283 ("target: Allow control CDBs with data > 1 page") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Reviewed-by: John Garry Reviewed-by: David Disseldorp Link: https://patch.msgid.link/20260610042245.35473-1-hexlabsecurity@proton.me Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: target: Bound PR-OUT TransportID parsing to the received buffer

2026-07-24T14:03:40+00:00

commit d04a179085c262c9ed577d0a4cbc6482ff1fd9a3 upstream. core_scsi3_decode_spec_i_port() and core_scsi3_emulate_register_and_move() hand the raw PERSISTENT RESERVE OUT parameter buffer to target_parse_pr_out_transport_id() without telling it how many bytes are valid. For an iSCSI TransportID (FORMAT CODE 01b), iscsi_parse_pr_out_transport_id() locates the ",i,0x" ISID separator with an unbounded strstr() (and on the error path prints the name with a further unbounded "%s"). An initiator can submit a TransportID whose iSCSI name contains neither a ",i,0x" substring nor a NUL terminator, filling the parameter list to its end, so the scan runs off the end of the buffer. When the parameter list spans more than one page the buffer is a multi-page vmap (transport_kmap_data_sg()), so the over-read walks into the trailing vmalloc guard page and oopses (KASAN: vmalloc-out-of-bounds in strstr). It is reachable by any fabric that delivers a PR OUT to a device exported through an iSCSI TPG, including a guest via vhost-scsi. Pass the number of received bytes down to the parser and validate the iSCSI TransportID's own self-described length (ADDITIONAL LENGTH + 4) once, up front: reject it if it is below the spc4r17 minimum or larger than the received buffer, then bound the separator search, the ISID walk and the name copy by that length. This is the length check the callers already perform after the parse (core_scsi3_decode_spec_i_port() compares tid_len against tpdl, core_scsi3_emulate_register_and_move() validates it against data_length), moved ahead of the scan. Also drop the unbounded "%s" of the unterminated name. Add per-format explicit name-length checks before copying into i_str, rather than silently truncating with min_t: for FORMAT CODE 00b reject if the descriptor body (tid_len - 4 bytes) cannot fit in i_str[TRANSPORT_IQN_LEN]; for FORMAT CODE 01b reject if the name portion (from &buf[4] up to the separator) cannot fit. Both checks make the bounds intent explicit at each format branch. While here, also reject a FORMAT CODE 01b TransportID whose ",i,0x" separator sits at the very end of the descriptor: that leaves an empty ISID and points the returned port nexus pointer at buf + tid_len, one past the descriptor, which the registration code (__core_scsi3_locate_pr_reg(), __core_scsi3_alloc_registration()) then dereferences as the ISID string -- the same over-read of the parameter buffer for a malformed descriptor. Fixes: c66ac9db8d4a ("[SCSI] target: Add LIO target core v4.0.0-rc6") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Reviewed-by: John Garry Reviewed-by: David Disseldorp Link: https://patch.msgid.link/20260611-b4-disp-9f20739e-v6-1-f6630e2aae44@proton.me Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: target: core: Generate correct identifiers for PR OUT transport IDs

2025-08-28T14:28:29+00:00

[ Upstream commit 6e0f6aa44b68335df404a2df955055f416b5f2aa ] Fix target_parse_pr_out_transport_id() to return a string representing the transport ID in a human-readable format (e.g., naa.xxxxxxxx...) for various SCSI protocol types (SAS, FCP, SRP, SBP). Previously, the function returned a pointer to the raw binary buffer, which was incorrectly compared against human-readable strings, causing comparisons to fail. Now, the function writes a properly formatted string into a buffer provided by the caller. The output format depends on the transport protocol: * SAS: 64-bit identifier, "naa." prefix. * FCP: 64-bit identifier, colon separated values. * SBP: 64-bit identifier, no prefix. * SRP: 128-bit identifier, "0x" prefix. * iSCSI: IQN string. Signed-off-by: Maurizio Lombardi Link: https://lore.kernel.org/r/20250714133738.11054-1-mlombard@redhat.com Reviewed-by: Dmitry Bogdanov Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: Fix NULL pointer dereference in core_scsi3_decode_spec_i_port()

2025-07-10T14:03:16+00:00

[ Upstream commit d8ab68bdb294b09a761e967dad374f2965e1913f ] The function core_scsi3_decode_spec_i_port(), in its error code path, unconditionally calls core_scsi3_lunacl_undepend_item() passing the dest_se_deve pointer, which may be NULL. This can lead to a NULL pointer dereference if dest_se_deve remains unset. SPC-3 PR SPEC_I_PT: Unable to locate dest_tpg Unable to handle kernel paging request at virtual address dfff800000000012 Call trace: core_scsi3_lunacl_undepend_item+0x2c/0xf0 [target_core_mod] (P) core_scsi3_decode_spec_i_port+0x120c/0x1c30 [target_core_mod] core_scsi3_emulate_pro_register+0x6b8/0xcd8 [target_core_mod] target_scsi3_emulate_pr_out+0x56c/0x840 [target_core_mod] Fix this by adding a NULL check before calling core_scsi3_lunacl_undepend_item() Signed-off-by: Maurizio Lombardi Link: https://lore.kernel.org/r/20250612101556.24829-1-mlombard@redhat.com Reviewed-by: Mike Christie Reviewed-by: John Meneghini Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

Merge patch series "Use block pr_ops in LIO"

2023-05-22T20:35:02+00:00

Mike Christie says: The patches in this thread allow us to use the block pr_ops with LIO's target_core_iblock module to support cluster applications in VMs. They were built over Linus's tree. They also apply over linux-next and Martin's tree and Jens's trees. Currently, to use windows clustering or linux clustering (pacemaker + cluster labs scsi fence agents) in VMs with LIO and vhost-scsi, you have to use tcmu or pscsi or use a cluster aware FS/framework for the LIO pr file. Setting up a cluster FS/framework is pain and waste when your real backend device is already a distributed device, and pscsi and tcmu are nice for specific use cases, but iblock gives you the best performance and allows you to use stacked devices like dm-multipath. So these patches allow iblock to work like pscsi/tcmu where they can pass a PR command to the backend module. And then iblock will use the pr_ops to pass the PR command to the real devices similar to what we do for unmap today. The patches are separated in the following groups: Patch 1 - 2: - Add block layer callouts for reading reservations and rename reservation error code. Patch 3 - 5: - SCSI support for new callouts. Patch 6: - DM support for new callouts. Patch 7 - 13: - NVMe support for new callouts. Patch 14 - 18: - LIO support for new callouts. This patchset has been tested with the libiscsi PGR ops and with window's failover cluster verification test. Note that for scsi backend devices we need this patchset: https://lore.kernel.org/linux-scsi/20230123221046.125483-1-michael.christie@oracle.com/T/#m4834a643ffb5bac2529d65d40906d3cfbdd9b1b7 to handle UAs. To reduce the size of this patchset that's being done separately to make reviewing easier. And to make merging easier this patchset and the one above do not have any conflicts so can be merged in different trees. Link: https://lore.kernel.org/r/20230407200551.12660-1-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: Report and detect unsupported PR commands

2023-04-12T01:55:36+00:00

The backend modules don't know about ports and I_T nexuses and the pr_ops callouts the modules will use don't support the old RESERVE/RELEASE commands. This patch has us report we don't support those types of commands and fail them. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230407200551.12660-18-michael.christie@oracle.com Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: target: Allow backends to hook into PR handling

2023-04-12T01:55:36+00:00

For the cases where you want to export a device to a VM via a single I_T nexus and want to passthrough the PR handling to the physical/real device you have to use pscsi or tcmu. Both are good for specific uses however for the case where you want good performance, and are not using SCSI devices directly (using DM/MD RAID or multipath devices) then we are out of luck. The following patches allow iblock to mimimally hook into the LIO PR code and then pass the PR handling to the physical device. Note that like with the tcmu an pscsi cases it's only supported when you export the device via one I_T nexus. This patch adds the initial LIO callouts. The next patch will modify iblock. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230407200551.12660-16-michael.christie@oracle.com Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

scsi: target: core: Use RTPI from target port

2023-03-10T02:29:23+00:00

Replace all references to RTPI from LUN field to se_portal_group field. It introduces consistent reporting of RTPI for all LUNs and all target ports. Reviewed-by: Christoph Hellwig Signed-off-by: Roman Bolshakov Signed-off-by: Dmitry Bogdanov Link: https://lore.kernel.org/r/20230301084512.21956-3-d.bogdanov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen

scsi: target: core: New key must be used for moved PR

2022-10-01T09:03:57+00:00

According to SPC4 5.12.8: e) Retain the reservation key specified in the SERVICE ACTION RESERVATION KEY field and associated information; But currently sa_res_key is only used for the not existing I_T nexus. Add a changing of the key for the existing I_T nexus the PR moved to. Link: https://lore.kernel.org/r/20220909090425.14479-5-d.bogdanov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Dmitry Bogdanov Signed-off-by: Martin K. Petersen

scsi: target: core: Abort all preempted regs if requested

2022-10-01T09:03:57+00:00

According to SPC the preempted commands shall be always aborted. SPC-4: 5.12.11.2.6 Preempting and aborting c) all commands from the I_T nexus(es) associated with the persistent reservations or registrations being preempted (i.e., preempted commands) except the PERSISTENT RESERVE OUT command itself shall be aborted as defined in SAM-5; Link: https://lore.kernel.org/r/20220909090425.14479-4-d.bogdanov@yadro.com Reviewed-by: Mike Christie Signed-off-by: Dmitry Bogdanov Signed-off-by: Martin K. Petersen