From: Showrya M N Date: Fri, 27 Jun 2025 11:23:29 +0000 (+0530) Subject: scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3ea3a256ed81f95ab0f3281a0e234b01a9cae605;p=thirdparty%2Fkernel%2Flinux.git 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 Signed-off-by: Showrya M N Signed-off-by: Potnuri Bharat Teja Link: https://lore.kernel.org/r/20250627112329.19763-1-showrya@chelsio.com Reviewed-by: Chris Leech Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 392d57e054db3..c9f410c509783 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -3185,7 +3185,8 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size, return NULL; conn = cls_conn->dd_data; - conn->dd_data = cls_conn->dd_data + sizeof(*conn); + if (dd_size) + conn->dd_data = cls_conn->dd_data + sizeof(*conn); conn->session = session; conn->cls_conn = cls_conn; conn->c_stage = ISCSI_CONN_INITIAL_STAGE;