From: =?ISO-8859-15?Q?Luk=E1=A8_Czerner?= Subject: Re: [PATCH 14/31] libext2fs: Fix ext2fs_open2() truncation of the superblock parameter Date: Mon, 7 Oct 2013 16:30:39 +0200 (CEST) Message-ID: References: <20131001012642.28415.89353.stgit@birch.djwong.org> <20131001012812.28415.49840.stgit@birch.djwong.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: tytso@mit.edu, linux-ext4@vger.kernel.org To: "Darrick J. Wong" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57005 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753401Ab3JGOas (ORCPT ); Mon, 7 Oct 2013 10:30:48 -0400 In-Reply-To: <20131001012812.28415.49840.stgit@birch.djwong.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 30 Sep 2013, Darrick J. Wong wrote: > Date: Mon, 30 Sep 2013 18:28:12 -0700 > From: Darrick J. Wong > To: tytso@mit.edu, darrick.wong@oracle.com > Cc: linux-ext4@vger.kernel.org > Subject: [PATCH 14/31] libext2fs: Fix ext2fs_open2() truncation of the > superblock parameter > > Since it's possible for very large filesystems to store backup superblocks at > very large (> 2^32) block numbers, we need to be able to handle the case of a > caller directing us to read one of these high-numbered backups. I do not think this is enough, because in ext2fs_open2() or rather ext2fs_open3() as you rename it we read the superblock block with io_channel_read_blk() which takes unsigned long as a block number rather than io_channel_read_blk64(). Having a simple test for this particular case might be useful. Thanks! -Lukas > > Signed-off-by: Darrick J. Wong > --- > debugfs/debugfs.c | 4 ++-- > e2fsck/journal.c | 6 +++--- > e2fsck/unix.c | 8 ++++---- > lib/ext2fs/ext2fs.h | 4 ++++ > lib/ext2fs/openfs.c | 13 +++++++++++-- > misc/dumpe2fs.c | 4 ++-- > 6 files changed, 26 insertions(+), 13 deletions(-) > > > diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c > index 2660218..da44ce4 100644 > --- a/debugfs/debugfs.c > +++ b/debugfs/debugfs.c > @@ -80,8 +80,8 @@ static void open_filesystem(char *device, int open_flags, blk64_t superblock, > if (catastrophic) > open_flags |= EXT2_FLAG_SKIP_MMP; > > - retval = ext2fs_open(device, open_flags, superblock, blocksize, > - unix_io_manager, ¤t_fs); > + retval = ext2fs_open3(device, NULL, open_flags, superblock, blocksize, > + unix_io_manager, ¤t_fs); > if (retval) { > com_err(device, retval, "while opening filesystem"); > current_fs = NULL; > diff --git a/e2fsck/journal.c b/e2fsck/journal.c > index 2509303..af35a38 100644 > --- a/e2fsck/journal.c > +++ b/e2fsck/journal.c > @@ -967,9 +967,9 @@ int e2fsck_run_ext3_journal(e2fsck_t ctx) > > ext2fs_mmp_stop(ctx->fs); > ext2fs_free(ctx->fs); > - retval = ext2fs_open(ctx->filesystem_name, EXT2_FLAG_RW, > - ctx->superblock, blocksize, io_ptr, > - &ctx->fs); > + retval = ext2fs_open3(ctx->filesystem_name, NULL, EXT2_FLAG_RW, > + ctx->superblock, blocksize, io_ptr, > + &ctx->fs); > if (retval) { > com_err(ctx->program_name, retval, > _("while trying to re-open %s"), > diff --git a/e2fsck/unix.c b/e2fsck/unix.c > index 0546653..fb41ca0 100644 > --- a/e2fsck/unix.c > +++ b/e2fsck/unix.c > @@ -1040,7 +1040,7 @@ static errcode_t try_open_fs(e2fsck_t ctx, int flags, io_manager io_ptr, > > *ret_fs = NULL; > if (ctx->superblock && ctx->blocksize) { > - retval = ext2fs_open2(ctx->filesystem_name, ctx->io_options, > + retval = ext2fs_open3(ctx->filesystem_name, ctx->io_options, > flags, ctx->superblock, ctx->blocksize, > io_ptr, ret_fs); > } else if (ctx->superblock) { > @@ -1051,7 +1051,7 @@ static errcode_t try_open_fs(e2fsck_t ctx, int flags, io_manager io_ptr, > ext2fs_free(*ret_fs); > *ret_fs = NULL; > } > - retval = ext2fs_open2(ctx->filesystem_name, > + retval = ext2fs_open3(ctx->filesystem_name, > ctx->io_options, flags, > ctx->superblock, blocksize, > io_ptr, ret_fs); > @@ -1059,7 +1059,7 @@ static errcode_t try_open_fs(e2fsck_t ctx, int flags, io_manager io_ptr, > break; > } > } else > - retval = ext2fs_open2(ctx->filesystem_name, ctx->io_options, > + retval = ext2fs_open3(ctx->filesystem_name, ctx->io_options, > flags, 0, 0, io_ptr, ret_fs); > > if (retval == 0) > @@ -1375,7 +1375,7 @@ failure: > * don't need to update the mount count and last checked > * fields in the backup superblock (the kernel doesn't update > * the backup superblocks anyway). With newer versions of the > - * library this flag is set by ext2fs_open2(), but we set this > + * library this flag is set by ext2fs_open3(), but we set this > * here just to be sure. (No, we don't support e2fsck running > * with some other libext2fs than the one that it was shipped > * with, but just in case....) > diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h > index c37e00b..d5d8d03 100644 > --- a/lib/ext2fs/ext2fs.h > +++ b/lib/ext2fs/ext2fs.h > @@ -1437,6 +1437,10 @@ extern errcode_t ext2fs_open2(const char *name, const char *io_options, > int flags, int superblock, > unsigned int block_size, io_manager manager, > ext2_filsys *ret_fs); > +extern errcode_t ext2fs_open3(const char *name, const char *io_options, > + int flags, blk64_t superblock, > + unsigned int block_size, io_manager manager, > + ext2_filsys *ret_fs); > extern blk64_t ext2fs_descriptor_block_loc2(ext2_filsys fs, > blk64_t group_block, dgrp_t i); > extern blk_t ext2fs_descriptor_block_loc(ext2_filsys fs, blk_t group_block, > diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c > index 89117f4..3c0bf14 100644 > --- a/lib/ext2fs/openfs.c > +++ b/lib/ext2fs/openfs.c > @@ -76,6 +76,15 @@ errcode_t ext2fs_open(const char *name, int flags, int superblock, > manager, ret_fs); > } > > +errcode_t ext2fs_open2(const char *name, const char *io_options, > + int flags, int superblock, > + unsigned int block_size, io_manager manager, > + ext2_filsys *ret_fs) > +{ > + return ext2fs_open3(name, io_options, flags, superblock, block_size, > + manager, ret_fs); > +} > + > /* > * Note: if superblock is non-zero, block-size must also be non-zero. > * Superblock and block_size can be zero to use the default size. > @@ -90,8 +99,8 @@ errcode_t ext2fs_open(const char *name, int flags, int superblock, > * EXT2_FLAG_64BITS - Allow 64-bit bitfields (needed for large > * filesystems) > */ > -errcode_t ext2fs_open2(const char *name, const char *io_options, > - int flags, int superblock, > +errcode_t ext2fs_open3(const char *name, const char *io_options, > + int flags, blk64_t superblock, > unsigned int block_size, io_manager manager, > ext2_filsys *ret_fs) > { > diff --git a/misc/dumpe2fs.c b/misc/dumpe2fs.c > index ae70f70..b139977 100644 > --- a/misc/dumpe2fs.c > +++ b/misc/dumpe2fs.c > @@ -611,7 +611,7 @@ int main (int argc, char ** argv) > for (use_blocksize = EXT2_MIN_BLOCK_SIZE; > use_blocksize <= EXT2_MAX_BLOCK_SIZE; > use_blocksize *= 2) { > - retval = ext2fs_open (device_name, flags, > + retval = ext2fs_open3(device_name, NULL, flags, > use_superblock, > use_blocksize, unix_io_manager, > &fs); > @@ -619,7 +619,7 @@ int main (int argc, char ** argv) > break; > } > } else > - retval = ext2fs_open (device_name, flags, use_superblock, > + retval = ext2fs_open3(device_name, NULL, flags, use_superblock, > use_blocksize, unix_io_manager, &fs); > if (retval) { > com_err (program_name, retval, _("while trying to open %s"), > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >