From 816d2c9cf7fb17fe808a081e076cb558f44ec30d Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 9 Sep 2013 10:39:29 -0400 Subject: [PATCH] libext2fs: ext2fs_dup_handle should not alias MMP buffers It turns out that resize2fs uses ext2fs_dup_handle to duplicate fs handles. If MMP is enabled, this causes both handles to share MMP buffers, which is bad news when it comes time to free both handles. Change the code to (we hope) fix this. This prevents resize2fs from failing with a double-free error when handed a MMP filesystem. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- lib/ext2fs/dupfs.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/lib/ext2fs/dupfs.c b/lib/ext2fs/dupfs.c index 64d31248a..02721e1a5 100644 --- a/lib/ext2fs/dupfs.c +++ b/lib/ext2fs/dupfs.c @@ -40,6 +40,9 @@ errcode_t ext2fs_dup_handle(ext2_filsys src, ext2_filsys *dest) fs->block_map = 0; fs->badblocks = 0; fs->dblist = 0; + fs->mmp_buf = 0; + fs->mmp_cmp = 0; + fs->mmp_fd = -1; io_channel_bumpcount(fs->io); if (fs->icache) @@ -87,6 +90,28 @@ errcode_t ext2fs_dup_handle(ext2_filsys src, ext2_filsys *dest) if (retval) goto errout; } + if (src->mmp_buf) { + retval = ext2fs_get_mem(src->blocksize, &fs->mmp_buf); + if (retval) + goto errout; + memcpy(fs->mmp_buf, src->mmp_buf, src->blocksize); + } + if (src->mmp_fd >= 0) { + fs->mmp_fd = dup(src->mmp_fd); + if (fs->mmp_fd < 0) { + retval = EXT2_ET_MMP_OPEN_DIRECT; + goto errout; + } + } + if (src->mmp_cmp) { + int align = ext2fs_get_dio_alignment(src->mmp_fd); + + retval = ext2fs_get_memalign(src->blocksize, align, + &fs->mmp_cmp); + if (retval) + goto errout; + memcpy(fs->mmp_cmp, src->mmp_cmp, src->blocksize); + } *dest = fs; return 0; errout: -- 2.47.2