From: "Vladimir 'phcoder' Serbinenko" <phcoder@gmail.com>
To: The development of GRUB 2 <grub-devel@gnu.org>
Subject: [PATCH 01/01] loader/bsd: Fix loading after unaligned module
Date: Sun, 8 Oct 2023 16:27:30 +0200 [thread overview]
Message-ID: <CAEaD8JM3buSEimOPjBGkaHoG=KLijEgMrJzvGOJyvnz1PUAZZg@mail.gmail.com> (raw)
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From fe519348967c7096e4b9466fc39bd393cd58319a Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Mon, 10 Jul 2023 17:17:35 +0200
Subject: [PATCH 01/01] loader/bsd: Fix loading after unaligned module
Current code implicitly assumes that aligning chunk_size + *kern_end is
the same as aligning on curload which is not the case because
chunk_size starts at zero even if *kern_end is unaligned and ALIGN_PAGE
moved curload to an aligned position but not *kern_end + chunk_size
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
---
grub-core/loader/i386/bsdXX.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/grub-core/loader/i386/bsdXX.c b/grub-core/loader/i386/bsdXX.c
index 09d909f1b..d3de8a29b 100644
--- a/grub-core/loader/i386/bsdXX.c
+++ b/grub-core/loader/i386/bsdXX.c
@@ -88,10 +88,9 @@ SUFFIX (grub_freebsd_load_elfmodule_obj) (struct grub_relocator *relocator,
Elf_Shnum shnum;
grub_addr_t curload, module;
grub_err_t err;
- grub_size_t chunk_size = 0;
void *chunk_src;
- curload = module = ALIGN_PAGE (*kern_end);
+ module = ALIGN_PAGE (*kern_end);
err = read_headers (file, argv[0], &e, &shdr);
if (err != GRUB_ERR_NONE)
@@ -101,6 +100,8 @@ SUFFIX (grub_freebsd_load_elfmodule_obj) (struct grub_relocator *relocator,
if (err != GRUB_ERR_NONE)
goto out;
+ curload = module;
+
for (s = shdr; s < (Elf_Shdr *) ((grub_uint8_t *) shdr + shnum * e.e_shentsize);
s = (Elf_Shdr *) ((grub_uint8_t *) s + e.e_shentsize))
{
@@ -108,21 +109,24 @@ SUFFIX (grub_freebsd_load_elfmodule_obj) (struct grub_relocator *relocator,
continue;
if (s->sh_addralign)
- chunk_size = ALIGN_UP (chunk_size + *kern_end, s->sh_addralign)
- - *kern_end;
+ curload = ALIGN_UP (curload, s->sh_addralign);
- chunk_size += s->sh_size;
+ curload += s->sh_size;
}
+ *kern_end = ALIGN_PAGE (curload);
+
{
grub_relocator_chunk_t ch;
err = grub_relocator_alloc_chunk_addr (relocator, &ch,
- module, chunk_size);
+ module, curload - module);
if (err != GRUB_ERR_NONE)
goto out;
chunk_src = get_virtual_current_address (ch);
}
+ curload = module;
+
for (s = shdr; s < (Elf_Shdr *) ((grub_uint8_t *) shdr + shnum * e.e_shentsize);
s = (Elf_Shdr *) ((grub_uint8_t *) s + e.e_shentsize))
{
@@ -141,13 +145,13 @@ SUFFIX (grub_freebsd_load_elfmodule_obj) (struct grub_relocator *relocator,
{
default:
case SHT_PROGBITS:
- err = load (file, argv[0], (grub_uint8_t *) chunk_src + curload - *kern_end,
+ err = load (file, argv[0], (grub_uint8_t *) chunk_src + curload - module,
s->sh_offset, s->sh_size);
if (err != GRUB_ERR_NONE)
goto out;
break;
case SHT_NOBITS:
- grub_memset ((grub_uint8_t *) chunk_src + curload - *kern_end, 0,
+ grub_memset ((grub_uint8_t *) chunk_src + curload - module, 0,
s->sh_size);
break;
}
--
2.42.0
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