From 720e6d218692b95af7f3b2032d53cf20f7c9ff9a Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Mon, 22 Jun 2015 09:42:48 +1000 Subject: [PATCH] xfs: fix remote symlinks on V5/CRC filesystems commit 2ac56d3d4bd625450a54d4c3f9292d58f6b88232 upstream. If we create a CRC filesystem, mount it, and create a symlink with a path long enough that it can't live in the inode, we get a very strange result upon remount: # ls -l mnt total 4 lrwxrwxrwx. 1 root root 929 Jun 15 16:58 link -> XSLM XSLM is the V5 symlink block header magic (which happens to be followed by a NUL, so the string looks terminated). xfs_readlink_bmap() advanced cur_chunk by the size of the header for CRC filesystems, but never actually used that pointer; it kept reading from bp->b_addr, which is the start of the block, rather than the start of the symlink data after the header. Looks like this problem goes back to v3.10. Fixing this gets us reading the proper link target, again. Signed-off-by: Eric Sandeen Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_symlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c index 195a403e1522..61dbe1958a30 100644 --- a/fs/xfs/xfs_symlink.c +++ b/fs/xfs/xfs_symlink.c @@ -272,7 +272,7 @@ xfs_readlink_bmap( cur_chunk += sizeof(struct xfs_dsymlink_hdr); } - memcpy(link + offset, bp->b_addr, byte_cnt); + memcpy(link + offset, cur_chunk, byte_cnt); pathlen -= byte_cnt; offset += byte_cnt; -- 2.20.1