[PATCH 3.2 099/102] ext2: Fix fs corruption in ext2_get_xip_mem()
3.2.64-rc1 review patch. If anyone has any objections, please let me know. -- From: Jan Kara commit 7ba3ec5749ddb61f79f7be17b5fd7720eebc52de upstream. 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 Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings --- fs/ext2/inode.c | 2 ++ fs/ext2/xip.c | 1 + 2 files changed, 3 insertions(+) --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -619,6 +619,8 @@ static int ext2_get_blocks(struct inode int count = 0; ext2_fsblk_t first_block = 0; + BUG_ON(maxblocks == 0); + depth = ext2_block_to_path(inode,iblock,offsets,_to_boundary); if (depth == 0) --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -37,6 +37,7 @@ __ext2_get_block(struct inode *inode, pg int rc; memset(, 0, sizeof(struct buffer_head)); + tmp.b_size = 1 << inode->i_blkbits; rc = ext2_get_block(inode, pgoff, , create); *result = tmp.b_blocknr; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3.2 099/102] ext2: Fix fs corruption in ext2_get_xip_mem()
3.2.64-rc1 review patch. If anyone has any objections, please let me know. -- From: Jan Kara j...@suse.cz commit 7ba3ec5749ddb61f79f7be17b5fd7720eebc52de upstream. 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...@gmail.com Signed-off-by: Jan Kara j...@suse.cz Signed-off-by: Ben Hutchings b...@decadent.org.uk --- fs/ext2/inode.c | 2 ++ fs/ext2/xip.c | 1 + 2 files changed, 3 insertions(+) --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -619,6 +619,8 @@ static int ext2_get_blocks(struct 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) --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -37,6 +37,7 @@ __ext2_get_block(struct inode *inode, pg 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; -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
