From: Ross Zwisler <ross.zwisler@linux.intel.com> To: linux-kernel@vger.kernel.org Cc: Ross Zwisler <ross.zwisler@linux.intel.com>, Alexander Viro <viro@zeniv.linux.org.uk>, Andrew Morton <akpm@linux-foundation.org>, Dan Williams <dan.j.williams@intel.com>, Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.com>, Matthew Wilcox <willy@linux.intel.com>, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org Subject: [PATCH 2/2] dax: fix bdev NULL pointer dereferences Date: Thu, 28 Jan 2016 12:35:04 -0700 [thread overview] Message-ID: <1454009704-25959-2-git-send-email-ross.zwisler@linux.intel.com> (raw) In-Reply-To: <1454009704-25959-1-git-send-email-ross.zwisler@linux.intel.com> There are a number of places in dax.c that look up the struct block_device associated with an inode. Previously this was done by just using inode->i_sb->s_bdev. This is correct for inodes that exist within the filesystems supported by DAX (ext2, ext4 & XFS), but when running DAX against raw block devices this value is NULL. This causes NULL pointer dereferences when these block_device pointers are used. Instead, for raw block devices we need to look up the struct block_device using I_BDEV(). This patch fixes all the block_device lookups in dax.c so that they work properly for both filesystems and raw block devices. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> --- fs/dax.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 4fd6b0c..e60a5a7 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -32,6 +32,9 @@ #include <linux/pfn_t.h> #include <linux/sizes.h> +#define DAX_BDEV(inode) (S_ISBLK(inode->i_mode) ? I_BDEV(inode) \ + : inode->i_sb->s_bdev) + static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax) { struct request_queue *q = bdev->bd_queue; @@ -65,7 +68,7 @@ static void dax_unmap_atomic(struct block_device *bdev, */ int dax_clear_blocks(struct inode *inode, sector_t block, long _size) { - struct block_device *bdev = inode->i_sb->s_bdev; + struct block_device *bdev = DAX_BDEV(inode); struct blk_dax_ctl dax = { .sector = block << (inode->i_blkbits - 9), .size = _size, @@ -246,7 +249,7 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, loff_t end = pos + iov_iter_count(iter); memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) { struct address_space *mapping = inode->i_mapping; @@ -468,7 +471,7 @@ int dax_writeback_mapping_range(struct address_space *mapping, loff_t start, loff_t end) { struct inode *inode = mapping->host; - struct block_device *bdev = inode->i_sb->s_bdev; + struct block_device *bdev = DAX_BDEV(inode); pgoff_t start_index, end_index, pmd_index; pgoff_t indices[PAGEVEC_SIZE]; struct pagevec pvec; @@ -608,7 +611,7 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, memset(&bh, 0, sizeof(bh)); block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); bh.b_size = PAGE_SIZE; repeat: @@ -827,7 +830,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, } memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); block = (sector_t)pgoff << (PAGE_SHIFT - blkbits); bh.b_size = PMD_SIZE; @@ -1080,7 +1083,7 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, BUG_ON((offset + length) > PAGE_CACHE_SIZE); memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); bh.b_size = PAGE_CACHE_SIZE; err = get_block(inode, index, &bh, 0); if (err < 0) -- 2.5.0
WARNING: multiple messages have this Message-ID (diff)
From: Ross Zwisler <ross.zwisler@linux.intel.com> To: linux-kernel@vger.kernel.org Cc: Ross Zwisler <ross.zwisler@linux.intel.com>, Alexander Viro <viro@zeniv.linux.org.uk>, Andrew Morton <akpm@linux-foundation.org>, Dan Williams <dan.j.williams@intel.com>, Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.com>, Matthew Wilcox <willy@linux.intel.com>, linux-fsdevel@vger.kernel.org, linux-nvdimm@ml01.01.org Subject: [PATCH 2/2] dax: fix bdev NULL pointer dereferences Date: Thu, 28 Jan 2016 12:35:04 -0700 [thread overview] Message-ID: <1454009704-25959-2-git-send-email-ross.zwisler@linux.intel.com> (raw) In-Reply-To: <1454009704-25959-1-git-send-email-ross.zwisler@linux.intel.com> There are a number of places in dax.c that look up the struct block_device associated with an inode. Previously this was done by just using inode->i_sb->s_bdev. This is correct for inodes that exist within the filesystems supported by DAX (ext2, ext4 & XFS), but when running DAX against raw block devices this value is NULL. This causes NULL pointer dereferences when these block_device pointers are used. Instead, for raw block devices we need to look up the struct block_device using I_BDEV(). This patch fixes all the block_device lookups in dax.c so that they work properly for both filesystems and raw block devices. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> --- fs/dax.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 4fd6b0c..e60a5a7 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -32,6 +32,9 @@ #include <linux/pfn_t.h> #include <linux/sizes.h> +#define DAX_BDEV(inode) (S_ISBLK(inode->i_mode) ? I_BDEV(inode) \ + : inode->i_sb->s_bdev) + static long dax_map_atomic(struct block_device *bdev, struct blk_dax_ctl *dax) { struct request_queue *q = bdev->bd_queue; @@ -65,7 +68,7 @@ static void dax_unmap_atomic(struct block_device *bdev, */ int dax_clear_blocks(struct inode *inode, sector_t block, long _size) { - struct block_device *bdev = inode->i_sb->s_bdev; + struct block_device *bdev = DAX_BDEV(inode); struct blk_dax_ctl dax = { .sector = block << (inode->i_blkbits - 9), .size = _size, @@ -246,7 +249,7 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, loff_t end = pos + iov_iter_count(iter); memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) { struct address_space *mapping = inode->i_mapping; @@ -468,7 +471,7 @@ int dax_writeback_mapping_range(struct address_space *mapping, loff_t start, loff_t end) { struct inode *inode = mapping->host; - struct block_device *bdev = inode->i_sb->s_bdev; + struct block_device *bdev = DAX_BDEV(inode); pgoff_t start_index, end_index, pmd_index; pgoff_t indices[PAGEVEC_SIZE]; struct pagevec pvec; @@ -608,7 +611,7 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, memset(&bh, 0, sizeof(bh)); block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); bh.b_size = PAGE_SIZE; repeat: @@ -827,7 +830,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, } memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); block = (sector_t)pgoff << (PAGE_SHIFT - blkbits); bh.b_size = PMD_SIZE; @@ -1080,7 +1083,7 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length, BUG_ON((offset + length) > PAGE_CACHE_SIZE); memset(&bh, 0, sizeof(bh)); - bh.b_bdev = inode->i_sb->s_bdev; + bh.b_bdev = DAX_BDEV(inode); bh.b_size = PAGE_CACHE_SIZE; err = get_block(inode, index, &bh, 0); if (err < 0) -- 2.5.0
next prev parent reply other threads:[~2016-01-28 19:35 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-28 19:35 [PATCH 1/2] block: fix pfn_mkwrite() DAX fault handler Ross Zwisler 2016-01-28 19:35 ` Ross Zwisler 2016-01-28 19:35 ` Ross Zwisler [this message] 2016-01-28 19:35 ` [PATCH 2/2] dax: fix bdev NULL pointer dereferences Ross Zwisler 2016-01-28 20:21 ` Dan Williams 2016-01-28 20:21 ` Dan Williams 2016-01-28 21:38 ` Christoph Hellwig 2016-01-29 18:28 ` Ross Zwisler 2016-01-29 23:34 ` Ross Zwisler 2016-01-30 0:18 ` Dan Williams 2016-01-31 22:44 ` Dave Chinner 2016-01-30 5:28 ` Matthew Wilcox 2016-01-30 6:01 ` Dan Williams 2016-01-30 7:08 ` Jared Hulbert 2016-01-31 2:32 ` Matthew Wilcox 2016-01-31 6:12 ` Ross Zwisler 2016-01-31 10:55 ` Matthew Wilcox 2016-01-31 16:38 ` Dan Williams 2016-01-31 18:07 ` Matthew Wilcox 2016-01-31 18:18 ` Dan Williams 2016-01-31 18:27 ` Matthew Wilcox 2016-01-31 18:50 ` Dan Williams 2016-01-31 19:51 ` Dan Williams 2016-02-01 13:44 ` Matthew Wilcox 2016-02-01 14:51 ` Jan Kara 2016-02-01 20:49 ` Matthew Wilcox 2016-02-01 21:47 ` Dave Chinner 2016-02-02 6:06 ` Jared Hulbert 2016-02-02 6:46 ` Dan Williams 2016-02-02 8:05 ` Jared Hulbert 2016-02-02 16:51 ` Dan Williams 2016-02-02 21:46 ` Jared Hulbert 2016-02-03 0:34 ` Matthew Wilcox 2016-02-03 1:21 ` Jared Hulbert 2016-02-02 11:17 ` Jan Kara 2016-02-02 16:33 ` Dan Williams 2016-02-02 16:46 ` Jan Kara 2016-02-02 17:10 ` Dan Williams 2016-02-02 17:34 ` Ross Zwisler 2016-02-02 17:46 ` Dan Williams 2016-02-02 17:47 ` Dan Williams 2016-02-02 18:24 ` Ross Zwisler 2016-02-02 18:46 ` Matthew Wilcox 2016-02-02 18:59 ` Dan Williams 2016-02-02 20:14 ` Matthew Wilcox 2016-02-03 11:09 ` Jan Kara 2016-02-03 10:46 ` Jan Kara 2016-02-03 20:13 ` Ross Zwisler 2016-02-04 9:15 ` Jan Kara 2016-02-04 23:38 ` Ross Zwisler 2016-02-06 23:15 ` Dave Chinner 2016-02-07 5:27 ` Ross Zwisler 2016-02-04 19:56 ` Ross Zwisler 2016-02-04 20:29 ` Jan Kara 2016-02-04 22:19 ` Ross Zwisler 2016-02-05 22:25 ` Ross Zwisler 2016-02-06 23:40 ` Dave Chinner 2016-02-07 6:43 ` Ross Zwisler 2016-02-08 13:48 ` Jan Kara 2016-02-07 8:38 ` Christoph Hellwig 2016-02-08 15:55 ` Ross Zwisler 2016-02-02 18:41 ` Ross Zwisler 2016-02-02 18:53 ` Ross Zwisler 2016-02-02 0:02 ` Ross Zwisler 2016-02-02 7:10 ` Dave Chinner 2016-02-02 10:34 ` Jan Kara
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