hpfs: better test for errors (3ebacb05) · Commits · 戴 / test

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> Cc: stable@kernel.org Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/hpfs/map.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -17,7 +17,8 @@ __le32 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;
		}

fs/hpfs/super.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -559,6 +559,12 @@ static int hpfs_fill_super(struct super_block s, void options, int silent)
		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;

Admin message