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| author | Jan Kara <jack@suse.cz> | 2013-11-05 01:15:38 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2013-11-05 11:26:47 +0100 |
| commit | 7ba3ec5749ddb61f79f7be17b5fd7720eebc52de (patch) | |
| tree | 01b2ff745122e12632c17142ce72748336886b03 | |
| parent | quota: info leak in quota_getquota() (diff) | |
| download | linux-7ba3ec5749ddb61f79f7be17b5fd7720eebc52de.tar.xz linux-7ba3ec5749ddb61f79f7be17b5fd7720eebc52de.zip | |
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>
| -rw-r--r-- | fs/ext2/inode.c | 2 | ||||
| -rw-r--r-- | fs/ext2/xip.c | 1 |
2 files changed, 3 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) diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c index 1c3312858fcf..e98171a11cfe 100644 --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -35,6 +35,7 @@ __ext2_get_block(struct inode *inode, pgoff_t pgoff, int create, int rc; memset(&tmp, 0, sizeof(struct buffer_head)); + tmp.b_size = 1 << inode->i_blkbits; rc = ext2_get_block(inode, pgoff, &tmp, create); *result = tmp.b_blocknr; |