CVE-2026-72084: Linux Vulnerability (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: target: Bound PR-OUT TransportID parsing to the received buffer 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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.21%

12.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 842248047ef28dbf3b3f7f49a0ec315054d4dab8; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 03fbc7de8d5e85fc8420e57e8304c855efd453ab; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 6ca5de8782e67573a61a6736b6dc0ffe58dcdf59; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 9298078a8f7d8181a04614a34ab655ccdf038204; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 004ccd2d3b4ac36a300e05e01df152e5c02a5a82; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < 555a89846ed888d7401b3f7200934c0fbedcbb46; >= c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5, < d04a179085c262c9ed577d0a4cbc6482ff1fd9a3
Linux	Linux	2.6.38

References

Timeline

Published: Aug 15, 2026
Last Modified: Aug 17, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-72084?

In the Linux kernel, the following vulnerability has been resolved: scsi: target: Bound PR-OUT TransportID parsing to the received buffer 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.

How severe is CVE-2026-72084?

CVE-2026-72084 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2026-72084?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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