[PATCH 14/31] libext2fs: Fix ext2fs_open2() truncation of the superblock parameter

Darrick J. Wong
2013-10-01T01:28:16Z

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.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
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, &current_fs);
+ retval = ext2fs_open3(device, NULL, open_flags, superblock, blocksize,
+ unix_io_manager, &current_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"),