| CVE: CVE-2022-1304 |
| Upstream-Status: Backport [ ab51d587bb9b229b1fade1afd02e1574c1ba5c76 ] |
| 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 |
| |