[PATCH 4.19 059/170] IB/hfi1: Incorrect sizing of sge for PIO will OOPs

From: Greg Kroah-Hartman
Date: Mon Jan 07 2019 - 07:49:01 EST

4.19-stable review patch. If anyone has any objections, please let me know.


From: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>

commit dbc2970caef74e8ff41923d302aa6fb5a4812d0e upstream.

An incorrect sge sizing in the HFI PIO path will cause an OOPs similar to

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [] hfi1_verbs_send_pio+0x3d8/0x530 [hfi1]
Oops: 0000 1 SMP
Call Trace:
? hfi1_verbs_send_dma+0xad0/0xad0 [hfi1]
hfi1_verbs_send+0xdf/0x250 [hfi1]
? make_rc_ack+0xa80/0xa80 [hfi1]
hfi1_do_send+0x192/0x430 [hfi1]
hfi1_do_send_from_rvt+0x10/0x20 [hfi1]
rvt_post_send+0x369/0x820 [rdmavt]
ib_uverbs_post_send+0x317/0x570 [ib_uverbs]
ib_uverbs_write+0x26f/0x420 [ib_uverbs]
? security_file_permission+0x21/0xa0
? mntput+0x24/0x40

Fix by adding the missing sizing check to correctly determine the sge

Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/infiniband/hw/hfi1/verbs.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/infiniband/hw/hfi1/verbs.c
+++ b/drivers/infiniband/hw/hfi1/verbs.c
@@ -1141,6 +1141,8 @@ int hfi1_verbs_send_pio(struct rvt_qp *q

if (slen > len)
slen = len;
+ if (slen > ss->sge.sge_length)
+ slen = ss->sge.sge_length;
rvt_update_sge(ss, slen, false);
seg_pio_copy_mid(pbuf, addr, slen);
len -= slen;