Patrick Williams | 03907ee | 2022-05-01 06:28:52 -0500 | [diff] [blame] | 1 | CVE: CVE-2022-1304 |
Andrew Geissler | d583833 | 2022-05-27 11:33:10 -0500 | [diff] [blame] | 2 | Upstream-Status: Backport [ ab51d587bb9b229b1fade1afd02e1574c1ba5c76 ] |
Patrick Williams | 03907ee | 2022-05-01 06:28:52 -0500 | [diff] [blame] | 3 | Signed-off-by: Ross Burton <ross.burton@arm.com> |
| 4 | |
| 5 | From 347084c9c1ad20f47dae16f5a3dcd8628d5fc7b0 Mon Sep 17 00:00:00 2001 |
| 6 | From: Lukas Czerner <lczerner@redhat.com> |
| 7 | Date: Thu, 21 Apr 2022 19:31:48 +0200 |
| 8 | Subject: [PATCH] e2fsprogs: add sanity check to extent manipulation |
| 9 | |
| 10 | It is possible to have a corrupted extent tree in such a way that a leaf |
| 11 | node contains zero extents in it. Currently if that happens and we try |
| 12 | to traverse the tree we can end up accessing wrong data, or possibly |
| 13 | even uninitialized memory. Make sure we don't do that. |
| 14 | |
| 15 | Additionally make sure that we have a sane number of bytes passed to |
| 16 | memmove() in ext2fs_extent_delete(). |
| 17 | |
| 18 | Note that e2fsck is currently unable to spot and fix such corruption in |
| 19 | pass1. |
| 20 | |
| 21 | Signed-off-by: Lukas Czerner <lczerner@redhat.com> |
| 22 | Reported-by: Nils Bars <nils_bars@t-online.de> |
| 23 | Addressess: https://bugzilla.redhat.com/show_bug.cgi?id=2068113 |
| 24 | --- |
| 25 | lib/ext2fs/extent.c | 8 ++++++++ |
| 26 | 1 file changed, 8 insertions(+) |
| 27 | |
| 28 | diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c |
| 29 | index b324c7b0..1a206a16 100644 |
| 30 | --- a/lib/ext2fs/extent.c |
| 31 | +++ b/lib/ext2fs/extent.c |
| 32 | @@ -495,6 +495,10 @@ retry: |
| 33 | ext2fs_le16_to_cpu(eh->eh_entries); |
| 34 | newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max); |
| 35 | |
| 36 | + /* Make sure there is at least one extent present */ |
| 37 | + if (newpath->left <= 0) |
| 38 | + return EXT2_ET_EXTENT_NO_DOWN; |
| 39 | + |
| 40 | if (path->left > 0) { |
| 41 | ix++; |
| 42 | newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block); |
| 43 | @@ -1630,6 +1634,10 @@ errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags) |
| 44 | |
| 45 | cp = path->curr; |
| 46 | |
| 47 | + /* Sanity check before memmove() */ |
| 48 | + if (path->left < 0) |
| 49 | + return EXT2_ET_EXTENT_LEAF_BAD; |
| 50 | + |
| 51 | if (path->left) { |
| 52 | memmove(cp, cp + sizeof(struct ext3_extent_idx), |
| 53 | path->left * sizeof(struct ext3_extent_idx)); |
| 54 | -- |
| 55 | 2.25.1 |
| 56 | |