From: Eric Sandeen Date: Sun, 21 Jun 2015 23:42:48 +0000 (+1000) Subject: xfs: fix remote symlinks on V5/CRC filesystems X-Git-Tag: v4.2-rc1~64^2^2~6 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=2ac56d3d4bd625450a54d4c3f9292d58f6b88232;p=linux.git xfs: fix remote symlinks on V5/CRC filesystems 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. Cc: stable@vger.kernel.org Signed-off-by: Eric Sandeen Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c index 3df411eadb86..40c076523cfa 100644 --- a/fs/xfs/xfs_symlink.c +++ b/fs/xfs/xfs_symlink.c @@ -104,7 +104,7 @@ 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;