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From: Mikulas Patocka <mpatocka@redhat.com>
To: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	Mike Snitzer <msnitzer@redhat.com>,
	John Dorminy <jdorminy@redhat.com>
Subject: [PATCH] dm-settings: fix a possible integer overflow in blk_queue_max_hw_sectors
Date: Fri, 20 Nov 2020 04:55:12 -0500 (EST)	[thread overview]
Message-ID: <alpine.LRH.2.02.2011200451180.28876@file01.intranet.prod.int.rdu2.redhat.com> (raw)

Fix a possible overflow due to shift left.
Also, replace the constant "9" with SECTOR_SHIFT.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 block/blk-settings.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-2.6/block/blk-settings.c
===================================================================
--- linux-2.6.orig/block/blk-settings.c	2020-11-19 21:20:18.000000000 +0100
+++ linux-2.6/block/blk-settings.c	2020-11-20 10:50:15.000000000 +0100
@@ -151,8 +151,8 @@ void blk_queue_max_hw_sectors(struct req
 	struct queue_limits *limits = &q->limits;
 	unsigned int max_sectors;
 
-	if ((max_hw_sectors << 9) < PAGE_SIZE) {
-		max_hw_sectors = 1 << (PAGE_SHIFT - 9);
+	if (max_hw_sectors < 1 << (PAGE_SHIFT - SECTOR_SHIFT)) {
+		max_hw_sectors = 1 << (PAGE_SHIFT - SECTOR_SHIFT);
 		printk(KERN_INFO "%s: set to minimum %d\n",
 		       __func__, max_hw_sectors);
 	}
@@ -161,7 +161,7 @@ void blk_queue_max_hw_sectors(struct req
 	max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
 	max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
 	limits->max_sectors = max_sectors;
-	q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9);
+	q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - SECTOR_SHIFT);
 }
 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
 


WARNING: multiple messages have this Message-ID (diff)
From: Mikulas Patocka <mpatocka@redhat.com>
To: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, dm-devel@redhat.com,
	Mike Snitzer <msnitzer@redhat.com>,
	John Dorminy <jdorminy@redhat.com>
Subject: [dm-devel] [PATCH] dm-settings: fix a possible integer overflow in blk_queue_max_hw_sectors
Date: Fri, 20 Nov 2020 04:55:12 -0500 (EST)	[thread overview]
Message-ID: <alpine.LRH.2.02.2011200451180.28876@file01.intranet.prod.int.rdu2.redhat.com> (raw)

Fix a possible overflow due to shift left.
Also, replace the constant "9" with SECTOR_SHIFT.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 block/blk-settings.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-2.6/block/blk-settings.c
===================================================================
--- linux-2.6.orig/block/blk-settings.c	2020-11-19 21:20:18.000000000 +0100
+++ linux-2.6/block/blk-settings.c	2020-11-20 10:50:15.000000000 +0100
@@ -151,8 +151,8 @@ void blk_queue_max_hw_sectors(struct req
 	struct queue_limits *limits = &q->limits;
 	unsigned int max_sectors;
 
-	if ((max_hw_sectors << 9) < PAGE_SIZE) {
-		max_hw_sectors = 1 << (PAGE_SHIFT - 9);
+	if (max_hw_sectors < 1 << (PAGE_SHIFT - SECTOR_SHIFT)) {
+		max_hw_sectors = 1 << (PAGE_SHIFT - SECTOR_SHIFT);
 		printk(KERN_INFO "%s: set to minimum %d\n",
 		       __func__, max_hw_sectors);
 	}
@@ -161,7 +161,7 @@ void blk_queue_max_hw_sectors(struct req
 	max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
 	max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
 	limits->max_sectors = max_sectors;
-	q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - 9);
+	q->backing_dev_info->io_pages = max_sectors >> (PAGE_SHIFT - SECTOR_SHIFT);
 }
 EXPORT_SYMBOL(blk_queue_max_hw_sectors);
 

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             reply	other threads:[~2020-11-20  9:55 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-20  9:55 Mikulas Patocka [this message]
2020-11-20  9:55 ` [dm-devel] [PATCH] dm-settings: fix a possible integer overflow in blk_queue_max_hw_sectors Mikulas Patocka

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