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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2018-10-30 20:26:15 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-13 22:15:12 +0300 |
| commit | fdd780d0a26070e59fe2c3690a776aad25227756 (patch) | |
| tree | ee7c0e92686bcbc9c1aa7a701c0b3b54c81a7f7b /fs/cramfs | |
| parent | 7f46d951fd3389089500623a9f026e4d25be823a (diff) | |
| download | linux-fdd780d0a26070e59fe2c3690a776aad25227756.tar.xz | |
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>
Diffstat (limited to 'fs/cramfs')
| -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 7919967488cb..011c6f53dcda 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -186,7 +186,8 @@ static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned i 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; } |