e2fsprogs: Fix CVE-2019-5094 in libsupport
authorHauke Mehrtens <hauke@hauke-m.de>
Fri, 22 Nov 2019 21:43:25 +0000 (22:43 +0100)
committerHauke Mehrtens <hauke@hauke-m.de>
Fri, 22 Nov 2019 21:54:28 +0000 (22:54 +0100)
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>
(cherry picked from commit 0062aad8ecc9bbe36c55895fd78fcaf9a406b006)

package/utils/e2fsprogs/Makefile
package/utils/e2fsprogs/patches/100-CVE-2019-5094-libsupport.patch [new file with mode: 0644]

index 1ed6280..b2b6ea3 100644 (file)
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=e2fsprogs
 PKG_VERSION:=1.44.5
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@KERNEL/linux/kernel/people/tytso/e2fsprogs/v$(PKG_VERSION)/
diff --git a/package/utils/e2fsprogs/patches/100-CVE-2019-5094-libsupport.patch b/package/utils/e2fsprogs/patches/100-CVE-2019-5094-libsupport.patch
new file mode 100644 (file)
index 0000000..c69f465
--- /dev/null
@@ -0,0 +1,203 @@
+From 09fe1fd2a1f9efc3091b4fc61f1876d0785956a8 Mon Sep 17 00:00:00 2001
+From: Theodore Ts'o <tytso@mit.edu>
+Date: Sun, 1 Sep 2019 00:59:16 -0400
+Subject: libsupport: add checks to prevent buffer overrun bugs in quota code
+
+A maliciously corrupted file systems can trigger buffer overruns in
+the quota code used by e2fsck.  To fix this, add sanity checks to the
+quota header fields as well as to block number references in the quota
+tree.
+
+Addresses: CVE-2019-5094
+Addresses: TALOS-2019-0887
+Signed-off-by: Theodore Ts'o <tytso@mit.edu>
+(cherry picked from commit 8dbe7b475ec5e91ed767239f0e85880f416fc384)
+---
+ lib/support/mkquota.c      |  1 +
+ lib/support/quotaio_tree.c | 71 ++++++++++++++++++++++++++++++----------------
+ lib/support/quotaio_v2.c   | 28 ++++++++++++++++++
+ 3 files changed, 76 insertions(+), 24 deletions(-)
+
+--- a/lib/support/mkquota.c
++++ b/lib/support/mkquota.c
+@@ -671,6 +671,7 @@ errcode_t quota_compare_and_update(quota
+       err = qh.qh_ops->scan_dquots(&qh, scan_dquots_callback, &scan_data);
+       if (err) {
+               log_debug("Error scanning dquots");
++              *usage_inconsistent = 1;
+               goto out_close_qh;
+       }
+--- a/lib/support/quotaio_tree.c
++++ b/lib/support/quotaio_tree.c
+@@ -540,6 +540,17 @@ struct dquot *qtree_read_dquot(struct qu
+       return dquot;
+ }
++static int check_reference(struct quota_handle *h, unsigned int blk)
++{
++      if (blk >= h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks) {
++              log_err("Illegal reference (%u >= %u) in %s quota file",
++                      blk, h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks,
++                      quota_type2name(h->qh_type));
++              return -1;
++      }
++      return 0;
++}
++
+ /*
+  * Scan all dquots in file and call callback on each
+  */
+@@ -558,7 +569,7 @@ static int report_block(struct dquot *dq
+       int entries, i;
+       if (!buf)
+-              return 0;
++              return -1;
+       set_bit(bitmap, blk);
+       read_blk(dquot->dq_h, blk, buf);
+@@ -580,23 +591,12 @@ static int report_block(struct dquot *dq
+       return entries;
+ }
+-static void check_reference(struct quota_handle *h, unsigned int blk)
+-{
+-      if (blk >= h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks)
+-              log_err("Illegal reference (%u >= %u) in %s quota file. "
+-                      "Quota file is probably corrupted.\n"
+-                      "Please run e2fsck (8) to fix it.",
+-                      blk,
+-                      h->qh_info.u.v2_mdqi.dqi_qtree.dqi_blocks,
+-                      quota_type2name(h->qh_type));
+-}
+-
+ static int report_tree(struct dquot *dquot, unsigned int blk, int depth,
+                      char *bitmap,
+                      int (*process_dquot) (struct dquot *, void *),
+                      void *data)
+ {
+-      int entries = 0, i;
++      int entries = 0, ret, i;
+       dqbuf_t buf = getdqbuf();
+       __le32 *ref = (__le32 *) buf;
+@@ -607,22 +607,40 @@ static int report_tree(struct dquot *dqu
+       if (depth == QT_TREEDEPTH - 1) {
+               for (i = 0; i < QT_BLKSIZE >> 2; i++) {
+                       blk = ext2fs_le32_to_cpu(ref[i]);
+-                      check_reference(dquot->dq_h, blk);
+-                      if (blk && !get_bit(bitmap, blk))
+-                              entries += report_block(dquot, blk, bitmap,
+-                                                      process_dquot, data);
++                      if (check_reference(dquot->dq_h, blk)) {
++                              entries = -1;
++                              goto errout;
++                      }
++                      if (blk && !get_bit(bitmap, blk)) {
++                              ret = report_block(dquot, blk, bitmap,
++                                                 process_dquot, data);
++                              if (ret < 0) {
++                                      entries = ret;
++                                      goto errout;
++                              }
++                              entries += ret;
++                      }
+               }
+       } else {
+               for (i = 0; i < QT_BLKSIZE >> 2; i++) {
+                       blk = ext2fs_le32_to_cpu(ref[i]);
+                       if (blk) {
+-                              check_reference(dquot->dq_h, blk);
+-                              entries += report_tree(dquot, blk, depth + 1,
+-                                                     bitmap, process_dquot,
+-                                                     data);
++                              if (check_reference(dquot->dq_h, blk)) {
++                                      entries = -1;
++                                      goto errout;
++                              }
++                              ret = report_tree(dquot, blk, depth + 1,
++                                                bitmap, process_dquot,
++                                                data);
++                              if (ret < 0) {
++                                      entries = ret;
++                                      goto errout;
++                              }
++                              entries += ret;
+                       }
+               }
+       }
++errout:
+       freedqbuf(buf);
+       return entries;
+ }
+@@ -642,6 +660,7 @@ int qtree_scan_dquots(struct quota_handl
+                     int (*process_dquot) (struct dquot *, void *),
+                     void *data)
+ {
++      int ret;
+       char *bitmap;
+       struct v2_mem_dqinfo *v2info = &h->qh_info.u.v2_mdqi;
+       struct qtree_mem_dqinfo *info = &v2info->dqi_qtree;
+@@ -655,10 +674,14 @@ int qtree_scan_dquots(struct quota_handl
+               ext2fs_free_mem(&dquot);
+               return -1;
+       }
+-      v2info->dqi_used_entries = report_tree(dquot, QT_TREEOFF, 0, bitmap,
+-                                             process_dquot, data);
++      ret = report_tree(dquot, QT_TREEOFF, 0, bitmap, process_dquot, data);
++      if (ret < 0)
++              goto errout;
++      v2info->dqi_used_entries = ret;
+       v2info->dqi_data_blocks = find_set_bits(bitmap, info->dqi_blocks);
++      ret = 0;
++errout:
+       ext2fs_free_mem(&bitmap);
+       ext2fs_free_mem(&dquot);
+-      return 0;
++      return ret;
+ }
+--- a/lib/support/quotaio_v2.c
++++ b/lib/support/quotaio_v2.c
+@@ -175,6 +175,8 @@ static int v2_check_file(struct quota_ha
+ static int v2_init_io(struct quota_handle *h)
+ {
+       struct v2_disk_dqinfo ddqinfo;
++      struct v2_mem_dqinfo *info;
++      __u64 filesize;
+       h->qh_info.u.v2_mdqi.dqi_qtree.dqi_entry_size =
+               sizeof(struct v2r1_disk_dqblk);
+@@ -185,6 +187,32 @@ static int v2_init_io(struct quota_handl
+                        sizeof(ddqinfo)) != sizeof(ddqinfo))
+               return -1;
+       v2_disk2memdqinfo(&h->qh_info, &ddqinfo);
++
++      /* Check to make sure quota file info is sane */
++      info = &h->qh_info.u.v2_mdqi;
++      if (ext2fs_file_get_lsize(h->qh_qf.e2_file, &filesize))
++              return -1;
++      if ((filesize > (1U << 31)) ||
++          (info->dqi_qtree.dqi_blocks >
++           (filesize + QT_BLKSIZE - 1) >> QT_BLKSIZE_BITS)) {
++              log_err("Quota inode %u corrupted: file size %llu; "
++                      "dqi_blocks %u", h->qh_qf.ino,
++                      filesize, info->dqi_qtree.dqi_blocks);
++              return -1;
++      }
++      if (info->dqi_qtree.dqi_free_blk >= info->dqi_qtree.dqi_blocks) {
++              log_err("Quota inode %u corrupted: free_blk %u; dqi_blocks %u",
++                      h->qh_qf.ino, info->dqi_qtree.dqi_free_blk,
++                      info->dqi_qtree.dqi_blocks);
++              return -1;
++      }
++      if (info->dqi_qtree.dqi_free_entry >= info->dqi_qtree.dqi_blocks) {
++              log_err("Quota inode %u corrupted: free_entry %u; "
++                      "dqi_blocks %u", h->qh_qf.ino,
++                      info->dqi_qtree.dqi_free_entry,
++                      info->dqi_qtree.dqi_blocks);
++              return -1;
++      }
+       return 0;
+ }