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authorChristoph Hellwig <hch@tuxera.com>2011-02-16 11:34:17 +0300
committerChristoph Hellwig <hch@lst.de>2011-06-30 15:40:58 +0400
commitbf1a1b31fa3ea24e3a90821d69a5c3da066f7d6c (patch)
tree32a751e5c58854fbb5aff9797fe73f6122e0b3ed /fs/hfsplus/extents.c
parent2b4f9ca8a575ce6d7ddb59d668e2be250bf86a8f (diff)
downloadlinux-bf1a1b31fa3ea24e3a90821d69a5c3da066f7d6c.tar.xz
hfsplus: fix overflow in hfsplus_get_block
For filesystems larger than 2TB the final sector number passed to map_bh might overflow the range representable in a 32-bit data type. Make sure we use a sector_t for it and the arithmetics calculating it. Signed-off-by: Christoph Hellwig <hch@tuxera.com>
Diffstat (limited to 'fs/hfsplus/extents.c')
-rw-r--r--fs/hfsplus/extents.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
index b1991a2a08e0..b9c1a4b5ba89 100644
--- a/fs/hfsplus/extents.c
+++ b/fs/hfsplus/extents.c
@@ -209,6 +209,7 @@ int hfsplus_get_block(struct inode *inode, sector_t iblock,
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res = -EIO;
u32 ablock, dblock, mask;
+ sector_t sector;
int was_dirty = 0;
int shift;
@@ -255,10 +256,12 @@ int hfsplus_get_block(struct inode *inode, sector_t iblock,
done:
dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
inode->i_ino, (long long)iblock, dblock);
+
mask = (1 << sbi->fs_shift) - 1;
- map_bh(bh_result, sb,
- (dblock << sbi->fs_shift) + sbi->blockoffset +
- (iblock & mask));
+ sector = ((sector_t)dblock << sbi->fs_shift) +
+ sbi->blockoffset + (iblock & mask);
+ map_bh(bh_result, sb, sector);
+
if (create) {
set_buffer_new(bh_result);
hip->phys_size += sb->s_blocksize;