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authorNicolas Pitre <nicolas.pitre@linaro.org>2018-10-30 20:26:15 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-13 22:15:12 +0300
commitfdd780d0a26070e59fe2c3690a776aad25227756 (patch)
treeee7c0e92686bcbc9c1aa7a701c0b3b54c81a7f7b /fs/cramfs
parent7f46d951fd3389089500623a9f026e4d25be823a (diff)
downloadlinux-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.c3
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;
}