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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2018-10-30 13:26:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-13 11:08:55 -0800 |
| commit | 9d9da6fe1f018669a0abd9d94f3810de5798a161 (patch) | |
| tree | ea3dbb1511059005b4ff6a4002e51e26a5fe7cb5 | |
| parent | 9632c0339b1217e280f693161498c3152c9c7bb3 (diff) | |
| download | linux-stable-9d9da6fe1f018669a0abd9d94f3810de5798a161.tar.gz linux-stable-9d9da6fe1f018669a0abd9d94f3810de5798a161.tar.bz2 linux-stable-9d9da6fe1f018669a0abd9d94f3810de5798a161.zip | |
Cramfs: fix abad comparison when wrap-arounds occur
commit 672ca9dd13f1aca0c17516f76fc5b0e8344b3e46 upstream.
It is possible for corrupted filesystem images to produce very large
block offsets that may wrap when a length is added, and wrongly pass
the buffer size test.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/cramfs/inode.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index f408994fc632..6e000392e4a4 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -202,7 +202,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, continue; blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT; blk_offset += offset; - if (blk_offset + len > BUFFER_SIZE) + if (blk_offset > BUFFER_SIZE || + blk_offset + len > BUFFER_SIZE) continue; return read_buffers[i] + blk_offset; } |