Medium · published September 4, 2025
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
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 2.6.27, < 5.4.297 | 5.4.297 |
| linux/linux_kernel | ≥ 5.5, < 5.10.241 | 5.10.241 |
| linux/linux_kernel | ≥ 5.11, < 5.15.190 | 5.15.190 |
| linux/linux_kernel | ≥ 5.16, < 6.1.149 | 6.1.149 |
| linux/linux_kernel | ≥ 6.2, < 6.6.103 | 6.6.103 |
| linux/linux_kernel | ≥ 6.7, < 6.12.43 | 6.12.43 |
| linux/linux_kernel | ≥ 6.13, < 6.15.11 | 6.15.11 |
| linux/linux_kernel | ≥ 6.16, < 6.16.2 | 6.16.2 |
| debian/debian_linux | all versions | — |