Critical severity · published Aug 15, 2026
CVE-2026-72084
scsi: target: Bound PR-OUT TransportID parsing to the received buffer
9.8
CVSS
0.7%
EPSS
No
On KEV
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.
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 55% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 88c67c3de914e19172e1d878a7625c5b06c20ec5; c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 842248047ef28dbf3b3f7f49a0ec315054d4dab8; c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 03fbc7de8d5e85fc8420e57e8304c855efd453ab; c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 6ca5de8782e67573a61a6736b6dc0ffe58dcdf59; c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 9298078a8f7d8181a04614a34ab655ccdf038204; c66ac9db8d4ad9994a02b3e933ea2ccc643e1fe5 before 004ccd2d3b4ac36a300e05e01df152e5c02a5a82; +3 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-72084
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-72084
git.kernel.org
https://git.kernel.org/stable/c/004ccd2d3b4ac36a300e05e01df152e5c02a5a82
git.kernel.org
https://git.kernel.org/stable/c/03fbc7de8d5e85fc8420e57e8304c855efd453ab
git.kernel.org
https://git.kernel.org/stable/c/555a89846ed888d7401b3f7200934c0fbedcbb46
git.kernel.org
https://git.kernel.org/stable/c/6ca5de8782e67573a61a6736b6dc0ffe58dcdf59
git.kernel.org
https://git.kernel.org/stable/c/842248047ef28dbf3b3f7f49a0ec315054d4dab8
git.kernel.org
https://git.kernel.org/stable/c/88c67c3de914e19172e1d878a7625c5b06c20ec5
More from Linux
9.8
CVE-2025-39682
tls: fix handling of zero-length records on the rx_list
8.8
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
7.8
CVE-2026-53362
ipv6: account for fraggap on the paged allocation path
7.8
CVE-2026-31431
crypto: algif_aead - Revert to operating out-of-place
7.8
CVE-2025-38352
posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
