[PATCH net] nvme-tcp: Fix comma-related oops

David Howells dhowells at redhat.com
Thu Jun 29 14:47:53 PDT 2023


Fix a comma that should be a semicolon.  The comma is at the end of an
if-body and thus makes the statement after (a bvec_set_page()) conditional
too, resulting in an oops because we didn't fill out the bio_vec[]:

    BUG: kernel NULL pointer dereference, address: 0000000000000008
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    ...
    Workqueue: nvme_tcp_wq nvme_tcp_io_work [nvme_tcp]
    RIP: 0010:skb_splice_from_iter+0xf1/0x370
    ...
    Call Trace:
     tcp_sendmsg_locked+0x3a6/0xdd0
     tcp_sendmsg+0x31/0x50
     inet_sendmsg+0x47/0x80
     sock_sendmsg+0x99/0xb0
     nvme_tcp_try_send_data+0x149/0x490 [nvme_tcp]
     nvme_tcp_try_send+0x1b7/0x300 [nvme_tcp]
     nvme_tcp_io_work+0x40/0xc0 [nvme_tcp]
     process_one_work+0x21c/0x430
     worker_thread+0x54/0x3e0
     kthread+0xf8/0x130

Fixes: 7769887817c3 ("nvme-tcp: Use sendmsg(MSG_SPLICE_PAGES) rather then sendpage")
Reported-by: Aurelien Aptel <aaptel at nvidia.com>
Link: https://lore.kernel.org/r/253mt0il43o.fsf@mtr-vdi-124.i-did-not-set--mail-host-address--so-tickle-me/
Signed-off-by: David Howells <dhowells at redhat.com>
cc: Sagi Grimberg <sagi at grimberg.me>
cc: Willem de Bruijn <willemb at google.com>
cc: Keith Busch <kbusch at kernel.org>
cc: Jens Axboe <axboe at fb.com>
cc: Christoph Hellwig <hch at lst.de>
cc: Chaitanya Kulkarni <kch at nvidia.com>
cc: "David S. Miller" <davem at davemloft.net>
cc: Eric Dumazet <edumazet at google.com>
cc: Jakub Kicinski <kuba at kernel.org>
cc: Paolo Abeni <pabeni at redhat.com>
cc: Jens Axboe <axboe at kernel.dk>
cc: Jens Axboe <axboe at kernel.dk>
cc: Matthew Wilcox <willy at infradead.org>
cc: linux-nvme at lists.infradead.org
cc: netdev at vger.kernel.org
---
 drivers/nvme/host/tcp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 3e7dd6f91832..9ce417cd32a7 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1014,7 +1014,7 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req)
 			msg.msg_flags |= MSG_MORE;
 
 		if (!sendpage_ok(page))
-			msg.msg_flags &= ~MSG_SPLICE_PAGES,
+			msg.msg_flags &= ~MSG_SPLICE_PAGES;
 
 		bvec_set_page(&bvec, page, len, offset);
 		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);




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