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author | Eric Sandeen <sandeen@redhat.com> | 2020-06-17 14:19:04 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-26 10:29:57 +0200 |
commit | fbbfd55a40d5d0806b59ee0403c75d5ac517533f (patch) | |
tree | 9f08e2849ec8a3e334f05889f8ccbd099ada55e8 /block | |
parent | d254a3e6c3b9a35c27c1bf7027be3ccb26b2d12a (diff) |
ext4: fix potential negative array index in do_split()
[ Upstream commit 5872331b3d91820e14716632ebb56b1399b34fe1 ]
If for any reason a directory passed to do_split() does not have enough
active entries to exceed half the size of the block, we can end up
iterating over all "count" entries without finding a split point.
In this case, count == move, and split will be zero, and we will
attempt a negative index into map[].
Guard against this by detecting this case, and falling back to
split-to-half-of-count instead; in this case we will still have
plenty of space (> half blocksize) in each split block.
Fixes: ef2b02d3e617 ("ext34: ensure do_split leaves enough free space in both blocks")
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f53e246b-647c-64bb-16ec-135383c70ad7@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
0 files changed, 0 insertions, 0 deletions