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authorJan Kara2013-11-05 01:15:38 +0100
committerJan Kara2013-11-05 11:26:47 +0100
commit7ba3ec5749ddb61f79f7be17b5fd7720eebc52de (patch)
tree01b2ff745122e12632c17142ce72748336886b03 /fs/ext2/inode.c
parentquota: info leak in quota_getquota() (diff)
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ext2: Fix fs corruption in ext2_get_xip_mem()
Commit 8e3dffc651cb "Ext2: mark inode dirty after the function dquot_free_block_nodirty is called" unveiled a bug in __ext2_get_block() called from ext2_get_xip_mem(). That function called ext2_get_block() mistakenly asking it to map 0 blocks while 1 was intended. Before the above mentioned commit things worked out fine by luck but after that commit we started returning that we allocated 0 blocks while we in fact allocated 1 block and thus allocation was looping until all blocks in the filesystem were exhausted. Fix the problem by properly asking for one block and also add assertion in ext2_get_blocks() to catch similar problems. Reported-and-tested-by: Andiry Xu <andiry.xu@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/ext2/inode.c')
-rw-r--r--fs/ext2/inode.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index c260de6d7b6d..8a337640a46a 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -632,6 +632,8 @@ static int ext2_get_blocks(struct inode *inode,
int count = 0;
ext2_fsblk_t first_block = 0;
+ BUG_ON(maxblocks == 0);
+
depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
if (depth == 0)