From bcd8e91f98c156f4b1ebcfacae675f9cfd962441 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 1 Sep 2018 12:45:04 -0400 Subject: ext4: avoid arithemetic overflow that can trigger a BUG A maliciously crafted file system can cause an overflow when the results of a 64-bit calculation is stored into a 32-bit length parameter. https://bugzilla.kernel.org/show_bug.cgi?id=200623 Signed-off-by: Theodore Ts'o Reported-by: Wen Xu Cc: stable@vger.kernel.org --- fs/ext4/ext4.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/ext4/ext4.h') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 249bcee4d7b2..ac05bd86643a 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -686,6 +686,9 @@ enum { /* Max physical block we can address w/o extents */ #define EXT4_MAX_BLOCK_FILE_PHYS 0xFFFFFFFF +/* Max logical block we can support */ +#define EXT4_MAX_LOGICAL_BLOCK 0xFFFFFFFF + /* * Structure of an inode on the disk */ -- cgit v1.2.3