Commit 01a9a8a9 authored May 21, 2014 by Filipe Manana Committed by Chris Mason Jun 06, 2014

Btrfs: send, fix corrupted path strings for long paths



If a path has more than 230 characters, we allocate a new buffer to
use for the path, but we were forgotting to copy the contents of the
previous buffer into the new one, which has random content from the
kmalloc call.

Test:

    mkfs.btrfs -f /dev/sdd
    mount /dev/sdd /mnt

    TEST_PATH="/mnt/fdmanana/.config/google-chrome-mysetup/Default/Pepper_Data/Shockwave_Flash/WritableRoot/#SharedObjects/JSHJ4ZKN/s.wsj.net/[[IMPORT]]/players.edgesuite.net/flash/plugins/osmf/advanced-streaming-plugin/v2.7/osmf1.6/Ak#"
    mkdir -p $TEST_PATH
    echo "hello world" > $TEST_PATH/amaiAdvancedStreamingPlugin.txt

    btrfs subvolume snapshot -r /mnt /mnt/mysnap1
    btrfs send /mnt/mysnap1 -f /tmp/1.snap

A test for xfstests follows.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Cc: Marc Merlin <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Chris Mason <clm@fb.com>

parent fad01e86

fs/btrfs/send.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -360,10 +360,13 @@ static int fs_path_ensure_buf(struct fs_path *p, int len)
		/*
		* First time the inline_buf does not suffice
		*/
		if (p->buf == p->inline_buf)
		if (p->buf == p->inline_buf) {
		tmp_buf = kmalloc(len, GFP_NOFS);
		else
		if (tmp_buf)
		memcpy(tmp_buf, p->buf, old_buf_len);
		} else {
		tmp_buf = krealloc(p->buf, len, GFP_NOFS);
		}
		if (!tmp_buf)
		return -ENOMEM;
		p->buf = tmp_buf;

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