From: Yogita Urade <yogita.ur...@windriver.com> An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.
References: https://nvd.nist.gov/vuln/detail/CVE-2023-4692 https://bugzilla.redhat.com/show_bug.cgi?id=2236613 Signed-off-by: Yogita Urade <yogita.ur...@windriver.com> --- .../grub/files/CVE-2023-4692.patch | 97 +++++++++++++++++++ meta/recipes-bsp/grub/grub2.inc | 1 + 2 files changed, 98 insertions(+) create mode 100644 meta/recipes-bsp/grub/files/CVE-2023-4692.patch diff --git a/meta/recipes-bsp/grub/files/CVE-2023-4692.patch b/meta/recipes-bsp/grub/files/CVE-2023-4692.patch new file mode 100644 index 0000000000..4780e35b7a --- /dev/null +++ b/meta/recipes-bsp/grub/files/CVE-2023-4692.patch @@ -0,0 +1,97 @@ +From 43651027d24e62a7a463254165e1e46e42aecdea Mon Sep 17 00:00:00 2001 +From: Maxim Suhanov <dfirb...@gmail.com> +Date: Thu, 16 Nov 2023 07:21:50 +0000 +Subject: [PATCH] fs/ntfs: Fix an OOB write when parsing the $ATTRIBUTE_LIST + attribute for the $MFT file + +When parsing an extremely fragmented $MFT file, i.e., the file described +using the $ATTRIBUTE_LIST attribute, current NTFS code will reuse a buffer +containing bytes read from the underlying drive to store sector numbers, +which are consumed later to read data from these sectors into another buffer. + +These sectors numbers, two 32-bit integers, are always stored at predefined +offsets, 0x10 and 0x14, relative to first byte of the selected entry within +the $ATTRIBUTE_LIST attribute. Usually, this won't cause any problem. + +However, when parsing a specially-crafted file system image, this may cause +the NTFS code to write these integers beyond the buffer boundary, likely +causing the GRUB memory allocator to misbehave or fail. These integers contain +values which are controlled by on-disk structures of the NTFS file system. + +Such modification and resulting misbehavior may touch a memory range not +assigned to the GRUB and owned by firmware or another EFI application/driver. + +This fix introduces checks to ensure that these sector numbers are never +written beyond the boundary. + +Fixes: CVE-2023-4692 + +Reported-by: Maxim Suhanov <dfirb...@gmail.com> +Signed-off-by: Maxim Suhanov <dfirb...@gmail.com> +Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com> + +CVE: CVE-2023-4692 +Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=43651027d24e62a7a463254165e1e46e42aecdea] + +Signed-off-by: Yogita Urade <yogita.ur...@windriver.com> +--- + grub-core/fs/ntfs.c | 18 +++++++++++++++++- + 1 file changed, 17 insertions(+), 1 deletion(-) + +diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c +index 2f34f76..6009e49 100644 +--- a/grub-core/fs/ntfs.c ++++ b/grub-core/fs/ntfs.c +@@ -184,7 +184,7 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr) + } + if (at->attr_end) + { +- grub_uint8_t *pa; ++ grub_uint8_t *pa, *pa_end; + + at->emft_buf = grub_malloc (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR); + if (at->emft_buf == NULL) +@@ -209,11 +209,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr) + } + at->attr_nxt = at->edat_buf; + at->attr_end = at->edat_buf + u32at (pa, 0x30); ++ pa_end = at->edat_buf + n; + } + else + { + at->attr_nxt = at->attr_end + u16at (pa, 0x14); + at->attr_end = at->attr_end + u32at (pa, 4); ++ pa_end = at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR); + } + at->flags |= GRUB_NTFS_AF_ALST; + while (at->attr_nxt < at->attr_end) +@@ -230,6 +232,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr) + at->flags |= GRUB_NTFS_AF_GPOS; + at->attr_cur = at->attr_nxt; + pa = at->attr_cur; ++ ++ if ((pa >= pa_end) || (pa_end - pa < 0x18)) ++ { ++ grub_error (GRUB_ERR_BAD_FS, "can\'t parse attribute list"); ++ return NULL; ++ } ++ + grub_set_unaligned32 ((char *) pa + 0x10, + grub_cpu_to_le32 (at->mft->data->mft_start)); + grub_set_unaligned32 ((char *) pa + 0x14, +@@ -240,6 +249,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr) + { + if (*pa != attr) + break; ++ ++ if ((pa >= pa_end) || (pa_end - pa < 0x18)) ++ { ++ grub_error (GRUB_ERR_BAD_FS, "can\'t parse attribute list"); ++ return NULL; ++ } ++ + if (read_attr + (at, pa + 0x10, + u32at (pa, 0x10) * (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR), +-- +2.40.0 diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc index c14fe315d3..aaee8a1e03 100644 --- a/meta/recipes-bsp/grub/grub2.inc +++ b/meta/recipes-bsp/grub/grub2.inc @@ -38,6 +38,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \ file://loader-efi-chainloader-Simplify-the-loader-state.patch \ file://commands-boot-Add-API-to-pass-context-to-loader.patch \ file://CVE-2022-28736-loader-efi-chainloader-Use-grub_loader_set_ex.patch \ + file://CVE-2023-4692.patch \ " SRC_URI[sha256sum] = "23b64b4c741569f9426ed2e3d0e6780796fca081bee4c99f62aa3f53ae803f5f" -- 2.35.5
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