]> git.baikalelectronics.ru Git - kernel.git/commit
erofs: handle corrupted images whose decompressed size less than it'd be
authorGao Xiang <gaoxiang25@huawei.com>
Wed, 26 Feb 2020 08:10:08 +0000 (16:10 +0800)
committerGao Xiang <gaoxiang25@huawei.com>
Tue, 3 Mar 2020 15:40:52 +0000 (23:40 +0800)
commit05b8e7341ea958738b441bd8384c325f2ddc740c
tree21ff8d425b797e1c4461535a783cd2477ba4e8b2
parentb80770e99e1d89c0bef4b6c80263fed5f2c0f413
erofs: handle corrupted images whose decompressed size less than it'd be

As Lasse pointed out, "Looking at fs/erofs/decompress.c,
the return value from LZ4_decompress_safe_partial is only
checked for negative value to catch errors. ... So if
I understood it correctly, if there is bad data whose
uncompressed size is much less than it should be, it can
leave part of the output buffer untouched and expose the
previous data as the file content. "

Let's fix it now.

Cc: Lasse Collin <lasse.collin@tukaani.org>
Fixes: d6c90688e3d0 ("staging: erofs: introduce generic decompression backend")
[ Gao Xiang: v5.3+, I will manually backport this to stable later. ]
Link: https://lore.kernel.org/r/20200226081008.86348-3-gaoxiang25@huawei.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
fs/erofs/decompressor.c