CVE-2025-38700

scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated

MEDIUM

5.5

CVSS Score

Published: September 4, 2025 at 03:32 PM UTC

Updated: October 19, 2026 at 09:10 PM UTC

3 products affected across 3 vendorsLinux KernelDebian LinuxSIMATIC CN 4100

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated In case of an ib_fast_reg_mr allocation failure during iSER setup, the machine hits a panic because iscsi_conn->dd_data is initialized unconditionally, even when no memory is allocated (dd_size == 0). This leads invalid pointer dereference during connection teardown. Fix by setting iscsi_conn->dd_data only if memory is actually allocated. Panic trace: ------------ iser: iser_create_fastreg_desc: Failed to allocate ib_fast_reg_mr err=-12 iser: iser_alloc_rx_descriptors: failed allocating rx descriptors / data buffers BUG: unable to handle page fault for address: fffffffffffffff8 RIP: 0010:swake_up_locked.part.5+0xa/0x40 Call Trace: complete+0x31/0x40 iscsi_iser_conn_stop+0x88/0xb0 [ib_iser] iscsi_stop_conn+0x66/0xc0 [scsi_transport_iscsi] iscsi_if_stop_conn+0x14a/0x150 [scsi_transport_iscsi] iscsi_if_rx+0x1135/0x1834 [scsi_transport_iscsi] ? netlink_lookup+0x12f/0x1b0 ? netlink_deliver_tap+0x2c/0x200 netlink_unicast+0x1ab/0x280 netlink_sendmsg+0x257/0x4f0 ? _copy_from_user+0x29/0x60 sock_sendmsg+0x5f/0x70

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Debian Linux · Debiandrupal

95%

11.0

Linux Kernel · Linux

95%

2.6.27 ≤ v < 5.4.2975.11 ≤ v < 5.15.1905.16 ≤ v < 6.1.1495.5 ≤ v < 5.10.2416.13 ≤ v < 6.15.116.16 ≤ v < 6.16.26.2 ≤ v < 6.6.1036.7 ≤ v < 6.12.432.6.275d91e209fb21fb9cc765729d4c6a85a9fb6c9187

Vendor states this is fixed in 2b242ea14386a510010eabfbfc3ce81a101f3802 (fixed)

Vendor states this is fixed in 35782c32528d82aa21f84cb5ceb2abd3526a8159 (fixed)

Vendor states this is fixed in 3ea3a256ed81f95ab0f3281a0e234b01a9cae605 (fixed)

Vendor states this is fixed in 66a373f50b4249d57f5a88c7be9676f9d5884865 (fixed)

Vendor states this is fixed in 9ea6d961566c7d762ed0204b06db05756fdda3b6 (fixed)

Vendor states this is fixed in a145c269dc5380c063a20a0db7e6df2995962e9d (fixed)

Vendor states this is fixed in a33d42b7fc24fe03f239fbb0880dd5b4b4b97c19 (fixed)

Vendor states this is fixed in f53af99f441ee79599d8df6113a7144d74cf9153 (fixed)

Vendor states this is fixed in fd5aad080edb501ab5c84b7623d612d0e3033403 (fixed)

Vendor states this is fixed in 2.6.27 (unaffected)

Vendor states this is fixed in 5.10.241 (unaffected)

Vendor states this is fixed in 5.15.190 (unaffected)

Vendor states this is fixed in 5.4.297 (unaffected)

Vendor states this is fixed in 6.1.149 (unaffected)

Vendor states this is fixed in 6.12.43 (unaffected)

Vendor states this is fixed in 6.15.11 (unaffected)

Vendor states this is fixed in 6.16.2 (unaffected)

Vendor states this is fixed in 6.17 (unaffected)

Vendor states this is fixed in 6.6.103 (unaffected)

SIMATIC CN 4100 · Siemens

60%

v < V5.0

Affected range stops below V5.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references