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authorTheodore Ts'o <tytso@mit.edu>2018-09-01 12:45:04 -0400
committerTheodore Ts'o <tytso@mit.edu>2018-09-01 12:45:04 -0400
commitbcd8e91f98c156f4b1ebcfacae675f9cfd962441 (patch)
treed6a8e8a1d4596f0c559efa1dc4d404d1260dc6a1 /fs/ext4/ext4.h
parent4d982e25d0bdc83d8c64e66fdeca0b89240b3b85 (diff)
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 <tytso@mit.edu> Reported-by: Wen Xu <wen.xu@gatech.edu> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs/ext4/ext4.h')
-rw-r--r--fs/ext4/ext4.h3
1 files changed, 3 insertions, 0 deletions
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
*/