e2fsprogs: Fix CVE-2019-5094 in libsupport
This adds the following patch from debian: https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/commit/?h=debian/stable&id=09fe1fd2a1f9efc3091b4fc61f1876d0785956a8 libsupport: add checks to prevent buffer overrun bugs in quota code Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
This commit is contained in:
Hauke Mehrtens
parent
a36c464efe
commit
0062aad8ec
@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
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PKG_NAME:=e2fsprogs
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PKG_VERSION:=1.44.5
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PKG_RELEASE:=1
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PKG_RELEASE:=2
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PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
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PKG_SOURCE_URL:=@KERNEL/linux/kernel/people/tytso/e2fsprogs/v$(PKG_VERSION)/
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@ -0,0 +1,203 @@
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From 09fe1fd2a1f9efc3091b4fc61f1876d0785956a8 Mon Sep 17 00:00:00 2001
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From: Theodore Ts'o <tytso@mit.edu>
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Date: Sun, 1 Sep 2019 00:59:16 -0400
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Subject: libsupport: add checks to prevent buffer overrun bugs in quota code
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A maliciously corrupted file systems can trigger buffer overruns in
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the quota code used by e2fsck. To fix this, add sanity checks to the
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quota header fields as well as to block number references in the quota
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tree.
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Addresses: CVE-2019-5094
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Addresses: TALOS-2019-0887
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Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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(cherry picked from commit 8dbe7b475ec5e91ed767239f0e85880f416fc384)
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---
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lib/support/mkquota.c | 1 +
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lib/support/quotaio_tree.c | 71 ++++++++++++++++++++++++++++++----------------
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lib/support/quotaio_v2.c | 28 ++++++++++++++++++
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3 files changed, 76 insertions(+), 24 deletions(-)
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--- a/lib/support/mkquota.c
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+++ b/lib/support/mkquota.c
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@@ -671,6 +671,7 @@ errcode_t quota_compare_and_update(quota
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err = qh.qh_ops->scan_dquots(&qh, scan_dquots_callback, &scan_data);
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if (err) {
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log_debug("Error scanning dquots");
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+ *usage_inconsistent = 1;
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goto out_close_qh;
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}
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--- a/lib/support/quotaio_tree.c
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+++ b/lib/support/quotaio_tree.c
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@@ -540,6 +540,17 @@ struct dquot *qtree_read_dquot(struct qu
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return dquot;
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}
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+static int check_reference(struct quota_handle *h, unsigned int blk)
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+{
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+ if (blk >= h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks) {
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+ log_err("Illegal reference (%u >= %u) in %s quota file",
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+ blk, h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks,
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+ quota_type2name(h->qh_type));
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+ return -1;
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+ }
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+ return 0;
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+}
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+
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/*
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* Scan all dquots in file and call callback on each
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*/
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@@ -558,7 +569,7 @@ static int report_block(struct dquot *dq
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int entries, i;
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if (!buf)
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- return 0;
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+ return -1;
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set_bit(bitmap, blk);
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read_blk(dquot->dq_h, blk, buf);
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@@ -580,23 +591,12 @@ static int report_block(struct dquot *dq
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return entries;
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}
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-static void check_reference(struct quota_handle *h, unsigned int blk)
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-{
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- if (blk >= h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks)
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- log_err("Illegal reference (%u >= %u) in %s quota file. "
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- "Quota file is probably corrupted.\n"
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- "Please run e2fsck (8) to fix it.",
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- blk,
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- h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks,
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- quota_type2name(h->qh_type));
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-}
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-
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static int report_tree(struct dquot *dquot, unsigned int blk, int depth,
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char *bitmap,
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int (*process_dquot) (struct dquot *, void *),
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void *data)
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{
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- int entries = 0, i;
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+ int entries = 0, ret, i;
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dqbuf_t buf = getdqbuf();
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__le32 *ref = (__le32 *) buf;
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@@ -607,22 +607,40 @@ static int report_tree(struct dquot *dqu
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if (depth == QT_TREEDEPTH - 1) {
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for (i = 0; i < QT_BLKSIZE >> 2; i++) {
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blk = ext2fs_le32_to_cpu(ref[i]);
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- check_reference(dquot->dq_h, blk);
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- if (blk && !get_bit(bitmap, blk))
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- entries += report_block(dquot, blk, bitmap,
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- process_dquot, data);
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+ if (check_reference(dquot->dq_h, blk)) {
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+ entries = -1;
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+ goto errout;
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+ }
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+ if (blk && !get_bit(bitmap, blk)) {
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+ ret = report_block(dquot, blk, bitmap,
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+ process_dquot, data);
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+ if (ret < 0) {
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+ entries = ret;
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+ goto errout;
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+ }
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+ entries += ret;
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+ }
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}
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} else {
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for (i = 0; i < QT_BLKSIZE >> 2; i++) {
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blk = ext2fs_le32_to_cpu(ref[i]);
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if (blk) {
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- check_reference(dquot->dq_h, blk);
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- entries += report_tree(dquot, blk, depth + 1,
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- bitmap, process_dquot,
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- data);
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+ if (check_reference(dquot->dq_h, blk)) {
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+ entries = -1;
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+ goto errout;
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+ }
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+ ret = report_tree(dquot, blk, depth + 1,
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+ bitmap, process_dquot,
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+ data);
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+ if (ret < 0) {
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+ entries = ret;
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+ goto errout;
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+ }
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+ entries += ret;
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}
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}
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}
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+errout:
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freedqbuf(buf);
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return entries;
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}
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@@ -642,6 +660,7 @@ int qtree_scan_dquots(struct quota_handl
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int (*process_dquot) (struct dquot *, void *),
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void *data)
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{
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+ int ret;
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char *bitmap;
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struct v2_mem_dqinfo *v2info = &h->qh_info.u.v2_mdqi;
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struct qtree_mem_dqinfo *info = &v2info->dqi_qtree;
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@@ -655,10 +674,14 @@ int qtree_scan_dquots(struct quota_handl
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ext2fs_free_mem(&dquot);
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return -1;
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}
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- v2info->dqi_used_entries = report_tree(dquot, QT_TREEOFF, 0, bitmap,
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- process_dquot, data);
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+ ret = report_tree(dquot, QT_TREEOFF, 0, bitmap, process_dquot, data);
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+ if (ret < 0)
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+ goto errout;
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+ v2info->dqi_used_entries = ret;
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v2info->dqi_data_blocks = find_set_bits(bitmap, info->dqi_blocks);
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+ ret = 0;
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+errout:
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ext2fs_free_mem(&bitmap);
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ext2fs_free_mem(&dquot);
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- return 0;
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+ return ret;
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}
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--- a/lib/support/quotaio_v2.c
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+++ b/lib/support/quotaio_v2.c
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@@ -175,6 +175,8 @@ static int v2_check_file(struct quota_ha
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static int v2_init_io(struct quota_handle *h)
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{
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struct v2_disk_dqinfo ddqinfo;
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+ struct v2_mem_dqinfo *info;
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+ __u64 filesize;
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h->qh_info.u.v2_mdqi.dqi_qtree.dqi_entry_size =
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sizeof(struct v2r1_disk_dqblk);
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@@ -185,6 +187,32 @@ static int v2_init_io(struct quota_handl
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sizeof(ddqinfo)) != sizeof(ddqinfo))
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return -1;
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v2_disk2memdqinfo(&h->qh_info, &ddqinfo);
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+
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+ /* Check to make sure quota file info is sane */
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+ info = &h->qh_info.u.v2_mdqi;
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+ if (ext2fs_file_get_lsize(h->qh_qf.e2_file, &filesize))
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+ return -1;
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+ if ((filesize > (1U << 31)) ||
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+ (info->dqi_qtree.dqi_blocks >
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+ (filesize + QT_BLKSIZE - 1) >> QT_BLKSIZE_BITS)) {
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+ log_err("Quota inode %u corrupted: file size %llu; "
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+ "dqi_blocks %u", h->qh_qf.ino,
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+ filesize, info->dqi_qtree.dqi_blocks);
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+ return -1;
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+ }
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+ if (info->dqi_qtree.dqi_free_blk >= info->dqi_qtree.dqi_blocks) {
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+ log_err("Quota inode %u corrupted: free_blk %u; dqi_blocks %u",
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+ h->qh_qf.ino, info->dqi_qtree.dqi_free_blk,
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+ info->dqi_qtree.dqi_blocks);
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+ return -1;
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+ }
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+ if (info->dqi_qtree.dqi_free_entry >= info->dqi_qtree.dqi_blocks) {
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+ log_err("Quota inode %u corrupted: free_entry %u; "
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+ "dqi_blocks %u", h->qh_qf.ino,
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+ info->dqi_qtree.dqi_free_entry,
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+ info->dqi_qtree.dqi_blocks);
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+ return -1;
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+ }
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return 0;
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}
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