Creating a file system with project quotas can fail if mke2fs is built
using hardening options. This is because quota_compute_usage() used
ext2fs_get_next_inode() instead of ext2fs_get_inode_full(), and a
small inode was passed into quota_data_add, when a large inode needs
to be used. As a result get_dq() would end up dereferencing undefined
space in the stack. Without the hardening options, this would be
zero, so "mke2fs -t ext4 -O project.quota -I 256 test.img" would work
essentially by accident.
Fix this by using ext2fs_get_inode_full() so that a large inode is
available to quota_data_inodes().
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
---
lib/support/mkquota.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/lib/support/mkquota.c b/lib/support/mkquota.c
index c5dd140..a432d4e 100644
--- a/lib/support/mkquota.c
+++ b/lib/support/mkquota.c
@@ -448,7 +448,8 @@ errcode_t quota_compute_usage(quota_ctx_t qctx)
ext2_filsys fs;
ext2_ino_t ino;
errcode_t ret;
- struct ext2_inode inode;
+ struct ext2_inode *inode;
+ int inode_size;
qsize_t space;
ext2_inode_scan scan;
@@ -461,27 +462,31 @@ errcode_t quota_compute_usage(quota_ctx_t qctx)
log_err("while opening inode scan. ret=%ld", ret);
return ret;
}
-
+ inode_size = fs->super->s_inode_size;
+ inode = malloc(inode_size);
+ if (!inode)
+ return ENOMEM;
while (1) {
- ret = ext2fs_get_next_inode(scan, &ino, &inode);
+ ret = ext2fs_get_next_inode_full(scan, &ino, inode, inode_size);
if (ret) {
log_err("while getting next inode. ret=%ld", ret);
ext2fs_close_inode_scan(scan);
+ free(inode);
return ret;
}
if (ino == 0)
break;
- if (inode.i_links_count &&
+ if (inode->i_links_count &&
(ino == EXT2_ROOT_INO ||
ino >= EXT2_FIRST_INODE(fs->super))) {
- space = ext2fs_inode_i_blocks(fs, &inode) << 9;
- quota_data_add(qctx, &inode, ino, space);
- quota_data_inodes(qctx, &inode, ino, +1);
+ space = ext2fs_inode_i_blocks(fs, inode) << 9;
+ quota_data_add(qctx, inode, ino, space);
+ quota_data_inodes(qctx, inode, ino, +1);
}
}
ext2fs_close_inode_scan(scan);
-
+ free(inode);
return 0;
}
--
2.5.0
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