Critical severity · published Aug 15, 2026
CVE-2026-72083
scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE
9.8
CVSS
0.7%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE 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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
4949314c7283ea4f9ade182ca599583b89f7edd6 before 7d56f5c868d92c9d504a34a3ea450bce481c7f63; 4949314c7283ea4f9ade182ca599583b89f7edd6 before 59a2a5a37dc49a641ad6bc64aee34e5a61025ffd; 4949314c7283ea4f9ade182ca599583b89f7edd6 before 9f8076cc73dfa6b10155978c160587e986b22169; 4949314c7283ea4f9ade182ca599583b89f7edd6 before a040004846f1fbe687f6ec76d9ccc27b4ead42e4; 4949314c7283ea4f9ade182ca599583b89f7edd6 before 05b3e37433cf2eaf8867f1c16528aa347bb212ab; 4949314c7283ea4f9ade182ca599583b89f7edd6 before cb7bdae7fba404852ade34b0c1445fbaf3e54fbb; +5 more · source: vendor