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authorMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>2013-07-04 18:42:29 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-13 10:34:43 -0700
commitc55035cb085d79311a429129183f43b85bac3994 (patch)
tree479ec12f7e19f4fcd33e9faff6cc17f84fdfad0a
parenta6ca6dff63f92efa17810ac0a4d33e3b63670482 (diff)
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hpfs: better test for errors
commit 3ebacb05044f82c5f0bb456a894eb9dc57d0ed90 upstream. The test if bitmap access is out of bound could errorneously pass if the device size is divisible by 16384 sectors and we are asking for one bitmap after the end. Check for invalid size in the superblock. Invalid size could cause integer overflows in the rest of the code. Signed-off-by: Mikulas Patocka <mpatocka@artax.karlin.mff.cuni.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/hpfs/map.c3
-rw-r--r--fs/hpfs/super.c8
2 files changed, 9 insertions, 2 deletions
diff --git a/fs/hpfs/map.c b/fs/hpfs/map.c
index a790821..ea3d1ca 100644
--- a/fs/hpfs/map.c
+++ b/fs/hpfs/map.c
@@ -17,7 +17,8 @@ unsigned int *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
struct quad_buffer_head *qbh, char *id)
{
secno sec;
- if (hpfs_sb(s)->sb_chk) if (bmp_block * 16384 > hpfs_sb(s)->sb_fs_size) {
+ unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
+ if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {
hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
return NULL;
}
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index 98580a3..f760c15 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -553,7 +553,13 @@ static int hpfs_fill_super(struct super_block *s, void *options, int silent)
sbi->sb_cp_table = NULL;
sbi->sb_c_bitmap = -1;
sbi->sb_max_fwd_alloc = 0xffffff;
-
+
+ if (sbi->sb_fs_size >= 0x80000000) {
+ hpfs_error(s, "invalid size in superblock: %08x",
+ (unsigned)sbi->sb_fs_size);
+ goto bail4;
+ }
+
/* Load bitmap directory */
if (!(sbi->sb_bmp_dir = hpfs_load_bitmap_directory(s, le32_to_cpu(superblock->bitmaps))))
goto bail4;