From: Xiaotian Feng Subject: [PATCH -mmotm 29/30] fix null pointer deref in swap_entry_free Date: Tue, 13 Jul 2010 06:22:18 -0400 Message-ID: <20100713102217.2835.75779.sendpatchset@danny.redhat> References: <20100713101650.2835.15245.sendpatchset@danny.redhat> Cc: riel@redhat.com, cl@linux-foundation.org, a.p.zijlstra@chello.nl, Xiaotian Feng , linux-kernel@vger.kernel.org, lwang@redhat.com, penberg@cs.helsinki.fi, akpm@linux-foundation.org, davem@davemloft.net To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org Return-path: In-Reply-To: <20100713101650.2835.15245.sendpatchset@danny.redhat> Sender: owner-linux-mm@kvack.org List-ID: >From ea7b13006f42f7dcadd1bfb874d5e525b4c259e3 Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Tue, 13 Jul 2010 13:44:08 +0800 Subject: [PATCH 29/30] fix null pointer deref in swap_entry_free Commit b3a27d uses p->bdev->bd_disk, this will lead a null pointer deref with swap over nfs. Signed-off-by: Xiaotian Feng --- mm/swapfile.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index d8a05e4..3eb53fc 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -577,7 +577,6 @@ static unsigned char swap_entry_free(struct swap_info_struct *p, /* free if no reference */ if (!usage) { - struct gendisk *disk = p->bdev->bd_disk; if (offset < p->lowest_bit) p->lowest_bit = offset; if (offset > p->highest_bit) @@ -587,9 +586,11 @@ static unsigned char swap_entry_free(struct swap_info_struct *p, swap_list.next = p->type; nr_swap_pages++; p->inuse_pages--; - if ((p->flags & SWP_BLKDEV) && - disk->fops->swap_slot_free_notify) - disk->fops->swap_slot_free_notify(p->bdev, offset); + if (p->flags & SWP_BLKDEV) { + struct gendisk *disk = p->bdev->bd_disk; + if (disk->fops->swap_slot_free_notify) + disk->fops->swap_slot_free_notify(p->bdev, offset); + } } return usage; -- 1.7.1.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org