From: "Darrick J. Wong" Subject: Re: [PATCH 14/31] libext2fs: Fix ext2fs_open2() truncation of the superblock parameter Date: Mon, 7 Oct 2013 11:42:47 -0700 Message-ID: <20131007184247.GC6860@birch.djwong.org> References: <20131001012642.28415.89353.stgit@birch.djwong.org> <20131001012812.28415.49840.stgit@birch.djwong.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: tytso@mit.edu, linux-ext4@vger.kernel.org To: =?utf-8?B?THVrw6HFoQ==?= Czerner Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:38669 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752384Ab3JGSm7 (ORCPT ); Mon, 7 Oct 2013 14:42:59 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Oct 07, 2013 at 04:30:39PM +0200, Luk=C3=A1=C5=A1 Czerner wrote= : > On Mon, 30 Sep 2013, Darrick J. Wong wrote: >=20 > > 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 > >=20 > > Since it's possible for very large filesystems to store backup supe= rblocks 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. >=20 > 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(). >=20 > Having a simple test for this particular case might be useful. Good catch! I've updated the patch. --D >=20 > Thanks! > -Lukas >=20 >=20 >=20 > >=20 > > 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(-) > >=20 > >=20 > > 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 ope= n_flags, blk64_t superblock, > > if (catastrophic) > > open_flags |=3D EXT2_FLAG_SKIP_MMP; > > =20 > > - retval =3D ext2fs_open(device, open_flags, superblock, blocksize, > > - unix_io_manager, ¤t_fs); > > + retval =3D ext2fs_open3(device, NULL, open_flags, superblock, blo= cksize, > > + unix_io_manager, ¤t_fs); > > if (retval) { > > com_err(device, retval, "while opening filesystem"); > > current_fs =3D 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) > > =20 > > ext2fs_mmp_stop(ctx->fs); > > ext2fs_free(ctx->fs); > > - retval =3D ext2fs_open(ctx->filesystem_name, EXT2_FLAG_RW, > > - ctx->superblock, blocksize, io_ptr, > > - &ctx->fs); > > + retval =3D 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, in= t flags, io_manager io_ptr, > > =20 > > *ret_fs =3D NULL; > > if (ctx->superblock && ctx->blocksize) { > > - retval =3D ext2fs_open2(ctx->filesystem_name, ctx->io_options, > > + retval =3D 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, in= t flags, io_manager io_ptr, > > ext2fs_free(*ret_fs); > > *ret_fs =3D NULL; > > } > > - retval =3D ext2fs_open2(ctx->filesystem_name, > > + retval =3D 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, in= t flags, io_manager io_ptr, > > break; > > } > > } else > > - retval =3D ext2fs_open2(ctx->filesystem_name, ctx->io_options, > > + retval =3D ext2fs_open3(ctx->filesystem_name, ctx->io_options, > > flags, 0, 0, io_ptr, ret_fs); > > =20 > > if (retval =3D=3D 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 *na= me, 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_opt= ions, > > + 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 gro= up_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 flag= s, int superblock, > > manager, ret_fs); > > } > > =20 > > +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_si= ze, > > + manager, ret_fs); > > +} > > + > > /* > > * Note: if superblock is non-zero, block-size must also be non-z= ero. > > * 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 =3D EXT2_MIN_BLOCK_SIZE; > > use_blocksize <=3D EXT2_MAX_BLOCK_SIZE; > > use_blocksize *=3D 2) { > > - retval =3D ext2fs_open (device_name, flags, > > + retval =3D 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 =3D ext2fs_open (device_name, flags, use_superblock, > > + retval =3D 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"), > >=20 > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-ext= 4" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > >=20 > -- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html