From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
George Zhang <georgezhang@vmware.com>,
Andy king <acking@vmware.com>, Dmitry Torokhov <dtor@vmware.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-fsdevel@vger.kernel.org
Subject: [PATCH 1/1] Fix: vmw_vmci driver get_user_pages_fast error handling
Date: Tue, 31 Oct 2017 19:00:38 -0400 [thread overview]
Message-ID: <20171031230038.7476-1-mathieu.desnoyers@efficios.com> (raw)
Comparing a signed return value against an unsigned num_pages
field performs the comparison as "unsigned", and therefore mistakenly
considers get_user_pages_fast() errors as success.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: George Zhang <georgezhang@vmware.com>
CC: Andy king <acking@vmware.com>
CC: Dmitry Torokhov <dtor@vmware.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: linux-fsdevel@vger.kernel.org
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index 8af5c2672f71..f71db848ce81 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -755,7 +755,7 @@ static int qp_host_get_user_memory(u64 produce_uva,
retval = get_user_pages_fast((uintptr_t) produce_uva,
produce_q->kernel_if->num_pages, 1,
produce_q->kernel_if->u.h.header_page);
- if (retval < produce_q->kernel_if->num_pages) {
+ if (retval < 0 || retval < produce_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(produce) failed (retval=%d)",
retval);
qp_release_pages(produce_q->kernel_if->u.h.header_page,
@@ -767,7 +767,7 @@ static int qp_host_get_user_memory(u64 produce_uva,
retval = get_user_pages_fast((uintptr_t) consume_uva,
consume_q->kernel_if->num_pages, 1,
consume_q->kernel_if->u.h.header_page);
- if (retval < consume_q->kernel_if->num_pages) {
+ if (retval < 0 || retval < consume_q->kernel_if->num_pages) {
pr_debug("get_user_pages_fast(consume) failed (retval=%d)",
retval);
qp_release_pages(consume_q->kernel_if->u.h.header_page,
--
2.11.0
next reply other threads:[~2017-10-31 23:01 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 23:00 Mathieu Desnoyers [this message]
2017-11-02 18:46 ` Al Viro
2017-11-02 18:54 ` Mathieu Desnoyers
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