linux-kernel - [PATCH 4.4 044/112] misc: mic: scif: Fix error handling path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201027134902.644799317@linuxfoundation.org>
Date:   Tue, 27 Oct 2020 14:49:14 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, John Hubbard <jhubbard@...dia.com>,
        Ira Weiny <ira.weiny@...el.com>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Souptick Joarder <jrdr.linux@...il.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.4 044/112] misc: mic: scif: Fix error handling path

From: Souptick Joarder <jrdr.linux@...il.com>

[ Upstream commit a81072a9c0ae734b7889929b0bc070fe3f353f0e ]

Inside __scif_pin_pages(), when map_flags != SCIF_MAP_KERNEL it
will call pin_user_pages_fast() to map nr_pages. However,
pin_user_pages_fast() might fail with a return value -ERRNO.

The return value is stored in pinned_pages->nr_pages. which in
turn is passed to unpin_user_pages(), which expects
pinned_pages->nr_pages >=0, else disaster.

Fix this by assigning pinned_pages->nr_pages to 0 if
pin_user_pages_fast() returns -ERRNO.

Fixes: ba612aa8b487 ("misc: mic: SCIF memory registration and unregistration")
Cc: John Hubbard <jhubbard@...dia.com>
Cc: Ira Weiny <ira.weiny@...el.com>
Cc: Dan Carpenter <dan.carpenter@...cle.com>
Reviewed-by: John Hubbard <jhubbard@...dia.com>
Signed-off-by: Souptick Joarder <jrdr.linux@...il.com>
Link: https://lore.kernel.org/r/1600570295-29546-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/misc/mic/scif/scif_rma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c
index 71c69e1c4ac05..4188b88c20a4a 100644
--- a/drivers/misc/mic/scif/scif_rma.c
+++ b/drivers/misc/mic/scif/scif_rma.c
@@ -1403,6 +1403,8 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot,
 				NULL);
 		up_write(&mm->mmap_sem);
 		if (nr_pages != pinned_pages->nr_pages) {
+			if (pinned_pages->nr_pages < 0)
+				pinned_pages->nr_pages = 0;
 			if (try_upgrade) {
 				if (ulimit)
 					__scif_dec_pinned_vm_lock(mm,
@@ -1423,7 +1425,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot,
 
 	if (pinned_pages->nr_pages < nr_pages) {
 		err = -EFAULT;
-		pinned_pages->nr_pages = nr_pages;
 		goto dec_pinned;
 	}
 
@@ -1436,7 +1437,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot,
 		__scif_dec_pinned_vm_lock(mm, nr_pages, 0);
 	/* Something went wrong! Rollback */
 error_unmap:
-	pinned_pages->nr_pages = nr_pages;
 	scif_destroy_pinned_pages(pinned_pages);
 	*pages = NULL;
 	dev_dbg(scif_info.mdev.this_device,
-- 
2.25.1