Messages in this thread | | | Date | Mon, 23 Apr 2018 02:03:52 -0400 | From | "Theodore Y. Ts'o" <> | Subject | Re: [PATCH 4.9 37/95] ext4: add validity checks for bitmap block numbers |
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On Sun, Apr 22, 2018 at 10:54:23PM +0100, Ben Hutchings wrote: > > offset = blk - group_first_block; > > - if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) > > + if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || > > + !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) > > Isn't sb->s_blocksize a count of bytes? If so, doesn't that mean that > we should be comparing with sb->s_blocksize * 8?
Yes, nice catch, Ben! Can we temporarily drop this patch from the stable queue until I can get a fix in?
In practice this shouldn't be a problem because of the default ext4 layout with flex_bg. But we should definitely get this fixed before we let this flow into the stable kernel.
- Ted
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