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authorRitesh Harjani <riteshh@linux.ibm.com>2020-05-05 17:43:14 +0200
committerTheodore Ts'o <tytso@mit.edu>2020-06-03 23:16:54 -0400
commit175efa81feb8405676e0136d97b10380179c92e0 (patch)
treededc073038563e46c894404a9802869434f2c12a /fs/ext4
parent9f364e1d9537d44fdf58deeeddb51277d8327ce5 (diff)
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
ext4 supports max number of logical blocks in a file to be 0xffffffff. (This is since ext4_extent's ee_block is __le32). This means that EXT4_MAX_LOGICAL_BLOCK should be 0xfffffffe (starting from 0 logical offset). This patch fixes this. The issue was seen when ext4 moved to iomap_fiemap API and when overlayfs was mounted on top of ext4. Since overlayfs was missing filemap_check_ranges(), so it could pass a arbitrary huge length which lead to overflow of map.m_len logic. This patch fixes that. Fixes: d3b6f23f7167 ("ext4: move ext4_fiemap to use iomap framework") Reported-by: syzbot+77fa5bdb65cc39711820@syzkaller.appspotmail.com Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200505154324.3226743-2-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/ext4.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a94e7aaea6e6..1eb07ca91fca 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -733,7 +733,7 @@ enum {
#define EXT4_MAX_BLOCK_FILE_PHYS 0xFFFFFFFF
/* Max logical block we can support */
-#define EXT4_MAX_LOGICAL_BLOCK 0xFFFFFFFF
+#define EXT4_MAX_LOGICAL_BLOCK 0xFFFFFFFE
/*
* Structure of an inode on the disk