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- From 1c7b619c84f229c1602c1958bcd054b6d9937562 Mon Sep 17 00:00:00 2001
- From: Alexey Makhalov <amakhalov@vmware.com>
- Date: Wed, 15 Jul 2020 06:42:37 +0000
- Subject: [PATCH] relocator: Protect grub_relocator_alloc_chunk_addr()
- input args against integer underflow/overflow
- MIME-Version: 1.0
- Content-Type: text/plain; charset=UTF-8
- Content-Transfer-Encoding: 8bit
- Use arithmetic macros from safemath.h to accomplish it. In this commit,
- I didn't want to be too paranoid to check every possible math equation
- for overflow/underflow. Only obvious places (with non zero chance of
- overflow/underflow) were refactored.
- Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
- Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
- Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
- ---
- grub-core/loader/i386/linux.c | 9 +++++++--
- grub-core/loader/i386/pc/linux.c | 9 +++++++--
- grub-core/loader/i386/xen.c | 12 ++++++++++--
- grub-core/loader/xnu.c | 11 +++++++----
- 4 files changed, 31 insertions(+), 10 deletions(-)
- diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
- index d0501e229..02a73463a 100644
- --- a/grub-core/loader/i386/linux.c
- +++ b/grub-core/loader/i386/linux.c
- @@ -36,6 +36,7 @@
- #include <grub/lib/cmdline.h>
- #include <grub/linux.h>
- #include <grub/machine/kernel.h>
- +#include <grub/safemath.h>
-
- GRUB_MOD_LICENSE ("GPLv3+");
-
- @@ -547,9 +548,13 @@ grub_linux_boot (void)
-
- {
- grub_relocator_chunk_t ch;
- + grub_size_t sz;
- +
- + if (grub_add (ctx.real_size, efi_mmap_size, &sz))
- + return GRUB_ERR_OUT_OF_RANGE;
- +
- err = grub_relocator_alloc_chunk_addr (relocator, &ch,
- - ctx.real_mode_target,
- - (ctx.real_size + efi_mmap_size));
- + ctx.real_mode_target, sz);
- if (err)
- return err;
- real_mode_mem = get_virtual_current_address (ch);
- diff --git a/grub-core/loader/i386/pc/linux.c b/grub-core/loader/i386/pc/linux.c
- index 47ea2945e..31f09922b 100644
- --- a/grub-core/loader/i386/pc/linux.c
- +++ b/grub-core/loader/i386/pc/linux.c
- @@ -35,6 +35,7 @@
- #include <grub/i386/floppy.h>
- #include <grub/lib/cmdline.h>
- #include <grub/linux.h>
- +#include <grub/safemath.h>
-
- GRUB_MOD_LICENSE ("GPLv3+");
-
- @@ -218,8 +219,12 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
- setup_sects = GRUB_LINUX_DEFAULT_SETUP_SECTS;
-
- real_size = setup_sects << GRUB_DISK_SECTOR_BITS;
- - grub_linux16_prot_size = grub_file_size (file)
- - - real_size - GRUB_DISK_SECTOR_SIZE;
- + if (grub_sub (grub_file_size (file), real_size, &grub_linux16_prot_size) ||
- + grub_sub (grub_linux16_prot_size, GRUB_DISK_SECTOR_SIZE, &grub_linux16_prot_size))
- + {
- + grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
- + goto fail;
- + }
-
- if (! grub_linux_is_bzimage
- && GRUB_LINUX_ZIMAGE_ADDR + grub_linux16_prot_size
- diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
- index 8f662c8ac..cd24874ca 100644
- --- a/grub-core/loader/i386/xen.c
- +++ b/grub-core/loader/i386/xen.c
- @@ -41,6 +41,7 @@
- #include <grub/linux.h>
- #include <grub/i386/memory.h>
- #include <grub/verify.h>
- +#include <grub/safemath.h>
-
- GRUB_MOD_LICENSE ("GPLv3+");
-
- @@ -636,6 +637,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
- grub_relocator_chunk_t ch;
- grub_addr_t kern_start;
- grub_addr_t kern_end;
- + grub_size_t sz;
-
- if (argc == 0)
- return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
- @@ -703,8 +705,14 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
-
- xen_state.max_addr = ALIGN_UP (kern_end, PAGE_SIZE);
-
- - err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch, kern_start,
- - kern_end - kern_start);
- +
- + if (grub_sub (kern_end, kern_start, &sz))
- + {
- + err = GRUB_ERR_OUT_OF_RANGE;
- + goto fail;
- + }
- +
- + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch, kern_start, sz);
- if (err)
- goto fail;
- kern_chunk_src = get_virtual_current_address (ch);
- diff --git a/grub-core/loader/xnu.c b/grub-core/loader/xnu.c
- index 77d7060e1..9ae4ceb35 100644
- --- a/grub-core/loader/xnu.c
- +++ b/grub-core/loader/xnu.c
- @@ -34,6 +34,7 @@
- #include <grub/env.h>
- #include <grub/i18n.h>
- #include <grub/verify.h>
- +#include <grub/safemath.h>
-
- GRUB_MOD_LICENSE ("GPLv3+");
-
- @@ -59,15 +60,17 @@ grub_xnu_heap_malloc (int size, void **src, grub_addr_t *target)
- {
- grub_err_t err;
- grub_relocator_chunk_t ch;
- + grub_addr_t tgt;
- +
- + if (grub_add (grub_xnu_heap_target_start, grub_xnu_heap_size, &tgt))
- + return GRUB_ERR_OUT_OF_RANGE;
-
- - err = grub_relocator_alloc_chunk_addr (grub_xnu_relocator, &ch,
- - grub_xnu_heap_target_start
- - + grub_xnu_heap_size, size);
- + err = grub_relocator_alloc_chunk_addr (grub_xnu_relocator, &ch, tgt, size);
- if (err)
- return err;
-
- *src = get_virtual_current_address (ch);
- - *target = grub_xnu_heap_target_start + grub_xnu_heap_size;
- + *target = tgt;
- grub_xnu_heap_size += size;
- grub_dprintf ("xnu", "val=%p\n", *src);
- return GRUB_ERR_NONE;
- --
- 2.26.2
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