| From | Kamal Mostafa <> | Subject | [PATCH 3.13 001/198] btrfs: fix defrag 32-bit integer overflow | Date | Tue, 15 Jul 2014 14:27:51 -0700 |
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3.13.11.5 -stable review patch. If anyone has any objections, please let me know.
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From: Justin Maggard <jmaggard10@gmail.com>
commit c41570c9d29764f797fa35490d72b7395a0105c3 upstream.
When defragging a very large file, the cluster variable can wrap its 32-bit signed int type and become negative, which eventually gets passed to btrfs_force_ra() as a very large unsigned long value. On 32-bit platforms, this eventually results in an Oops from the SLAB allocator.
Change the cluster and max_cluster signed int variables to unsigned long to match the readahead functions. This also allows the min() comparison in btrfs_defrag_file() to work as intended.
Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Cc: Joseph Salisbury <joseph.salisbury@canonical.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- fs/btrfs/ioctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 9f831bb..043d6cd 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1011,7 +1011,7 @@ out: static int cluster_pages_for_defrag(struct inode *inode, struct page **pages, unsigned long start_index, - int num_pages) + unsigned long num_pages) { unsigned long file_end; u64 isize = i_size_read(inode); @@ -1169,8 +1169,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, int defrag_count = 0; int compress_type = BTRFS_COMPRESS_ZLIB; int extent_thresh = range->extent_thresh; - int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; - int cluster = max_cluster; + unsigned long max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; + unsigned long cluster = max_cluster; u64 new_align = ~((u64)128 * 1024 - 1); struct page **pages = NULL; -- 1.9.1
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