This patch avoids that sending a WRITE SAME command to the iSCSI
initiator triggers the following:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000014
TARGET_CORE[iSCSI]: Expected Transfer Length: 260096 does not match SCSI CDB
Length: 512 for SAM Opcode: 0x41
IP: iscsi_tcp_segment_done+0x20b/0x310 [libiscsi_tcp]
Oops: 0000 [#1] SMP
Modules linked in: target_core_user uio target_core_iblock target_core_file
iscsi_target_mod target_core_mod netconsole configfs crct10dif_pclmul
crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 crypto_simd cryptd
glue_helper virtio_console virtio_rng virtio_balloon serio_raw i2c_piix4
acpi_cpufreq button iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ext4
jbd2 mbcache virtio_blk virtio_net psmouse floppy drm_kms_helper syscopyarea
sysfillrect sysimgblt fb_sys_fops ttm drm virtio_pci
CPU: 2 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0-rc5-debug+ #3
Workqueue: iscsi_q_0 iscsi_xmitworker [libiscsi]
RIP: 0010:iscsi_tcp_segment_done+0x20b/0x310 [libiscsi_tcp]
Call Trace:
iscsi_sw_tcp_xmit_segment+0x84/0x120 [iscsi_tcp]
iscsi_sw_tcp_pdu_xmit+0x51/0x180 [iscsi_tcp]
iscsi_tcp_task_xmit+0xb3/0x290 [libiscsi_tcp]
iscsi_xmit_task+0x4e/0xc0 [libiscsi]
iscsi_xmitworker+0x243/0x330 [libiscsi]
process_one_work+0x1d8/0x4b0
worker_thread+0x49/0x4a0
kthread+0x102/0x140
Fixes: f80de881d8df ("sd: remove __data_len hack for WRITE SAME")
Cc: Christoph Hellwig <h...@lst.de>
Cc: Hannes Reinecke <h...@suse.com>
Cc: Sagi Grimberg <s...@grimberg.me>
Cc: Jens Axboe <ax...@fb.com>
Cc: Mike Christie <mchri...@redhat.com>
---
drivers/scsi/scsi_lib.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e9e1e141af9c..004f17042081 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1000,6 +1000,18 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned
int good_bytes)
}
}
+static u64 sg_data_length(struct sg_table *sg_table)
+{
+ struct scatterlist *sg;
+ int i;
+ u64 len = 0;
+
+ for_each_sg(sg_table->sgl, sg, sg_table->nents, i)
+ len += sg->length;
+
+ return len;
+}
+
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
{
int count;
@@ -1018,7 +1030,7 @@ static int scsi_init_sgtable(struct request *req, struct
scsi_data_buffer *sdb)
count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
BUG_ON(count > sdb->table.nents);
sdb->table.nents = count;
- sdb->length = blk_rq_payload_bytes(req);
+ sdb->length = sg_data_length(&sdb->table);
return BLKPREP_OK;
}
--
2.11.0
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