e2fsprogs: fix CVE-2022-1304

Backport a submitted patch to fix CVE-2022-1304.

(From OE-Core rev: 31fd4ca6fa85ed1e62faf37e6d7bed5b558cb309)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 57 insertions, 0 deletions

diff --git a/meta/recipes-devtools/e2fsprogs/e2fsprogs/extents.patch b/meta/recipes-devtools/e2fsprogs/e2fsprogs/extents.patch
new file mode 100644
index 0000000000..ffaecc622a
--- /dev/null
+++ b/meta/recipes-devtools/e2fsprogs/e2fsprogs/extents.patch
@@ -0,0 +1,56 @@
+CVE: CVE-2022-1304
+Upstream-Status: Submitted [https://lore.kernel.org/linux-ext4/20220421173148.20193-1-lczerner@redhat.com/]
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+
+From 347084c9c1ad20f47dae16f5a3dcd8628d5fc7b0 Mon Sep 17 00:00:00 2001
+From: Lukas Czerner <lczerner@redhat.com>
+Date: Thu, 21 Apr 2022 19:31:48 +0200
+Subject: [PATCH] e2fsprogs: add sanity check to extent manipulation
+
+It is possible to have a corrupted extent tree in such a way that a leaf
+node contains zero extents in it. Currently if that happens and we try
+to traverse the tree we can end up accessing wrong data, or possibly
+even uninitialized memory. Make sure we don't do that.
+
+Additionally make sure that we have a sane number of bytes passed to
+memmove() in ext2fs_extent_delete().
+
+Note that e2fsck is currently unable to spot and fix such corruption in
+pass1.
+
+Signed-off-by: Lukas Czerner <lczerner@redhat.com>
+Reported-by: Nils Bars <nils_bars@t-online.de>
+Addressess: https://bugzilla.redhat.com/show_bug.cgi?id=2068113
+---
+ lib/ext2fs/extent.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
+index b324c7b0..1a206a16 100644
+--- a/lib/ext2fs/extent.c
++++ b/lib/ext2fs/extent.c
+@@ -495,6 +495,10 @@ retry:
+                        ext2fs_le16_to_cpu(eh->eh_entries);
+                newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
+ 
++               /* Make sure there is at least one extent present */
++               if (newpath->left <= 0)
++                       return EXT2_ET_EXTENT_NO_DOWN;
++
+                if (path->left > 0) {
+                        ix++;
+                        newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block);
+@@ -1630,6 +1634,10 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
+ 
+        cp = path->curr;
+ 
++       /* Sanity check before memmove() */
++       if (path->left < 0)
++               return EXT2_ET_EXTENT_LEAF_BAD;
++
+        if (path->left) {
+                memmove(cp, cp + sizeof(struct ext3_extent_idx),
+                        path->left * sizeof(struct ext3_extent_idx));
+-- 
+2.25.1
+
diff --git a/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.46.5.bb b/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.46.5.bb
index 16c183eed3..ec48f419c7 100644
--- a/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.46.5.bb
+++ b/meta/recipes-devtools/e2fsprogs/e2fsprogs_1.46.5.bb
@@ -4,6 +4,7 @@ SRC_URI += "file://remove.ldconfig.call.patch \
            file://run-ptest \
            file://ptest.patch \
            file://mkdir_p.patch \
+           file://extents.patch \
            "
 SRC_URI:append:class-native = " \
            file://e2fsprogs-fix-missing-check-for-permission-denied.patch \