Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'efi_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Borislav Petkov:
"A batch of fixes for the arm64 stub image loader:
- fix a logic bug that can make the random page allocator fail
spuriously
- force reallocation of the Image when it overlaps with firmware
reserved memory regions
- fix an oversight that defeated on optimization introduced earlier
where images loaded at a suitable offset are never moved if booting
without randomization
- complain about images that were not loaded at the right offset by
the firmware image loader"
* tag 'efi_urgent_for_v5.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/libstub: arm64: Double check image alignment at entry
efi/libstub: arm64: Warn when efi_random_alloc() fails
efi/libstub: arm64: Relax 2M alignment again for relocatable kernels
efi/libstub: arm64: Force Image reallocation if BSS was not reserved
arm64: efi: kaslr: Fix occasional random alloc (and boot) failure
+63
-10
+61
-10
drivers/firmware/efi/libstub/arm64-stub.c
+61
-10
drivers/firmware/efi/libstub/arm64-stub.c
···
35
35
}
36
36
37
37
/*
38
-
* Although relocatable kernels can fix up the misalignment with respect to
39
-
* MIN_KIMG_ALIGN, the resulting virtual text addresses are subtly out of
40
-
* sync with those recorded in the vmlinux when kaslr is disabled but the
41
-
* image required relocation anyway. Therefore retain 2M alignment unless
42
-
* KASLR is in use.
38
+
* Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
39
+
* to provide space, and fail to zero it). Check for this condition by double
40
+
* checking that the first and the last byte of the image are covered by the
41
+
* same EFI memory map entry.
43
42
*/
44
-
static u64 min_kimg_align(void)
43
+
static bool check_image_region(u64 base, u64 size)
45
44
{
46
-
return efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
45
+
unsigned long map_size, desc_size, buff_size;
46
+
efi_memory_desc_t *memory_map;
47
+
struct efi_boot_memmap map;
48
+
efi_status_t status;
49
+
bool ret = false;
50
+
int map_offset;
51
+
52
+
map.map = &memory_map;
53
+
map.map_size = &map_size;
54
+
map.desc_size = &desc_size;
55
+
map.desc_ver = NULL;
56
+
map.key_ptr = NULL;
57
+
map.buff_size = &buff_size;
58
+
59
+
status = efi_get_memory_map(&map);
60
+
if (status != EFI_SUCCESS)
61
+
return false;
62
+
63
+
for (map_offset = 0; map_offset < map_size; map_offset += desc_size) {
64
+
efi_memory_desc_t *md = (void *)memory_map + map_offset;
65
+
u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
66
+
67
+
/*
68
+
* Find the region that covers base, and return whether
69
+
* it covers base+size bytes.
70
+
*/
71
+
if (base >= md->phys_addr && base < end) {
72
+
ret = (base + size) <= end;
73
+
break;
74
+
}
75
+
}
76
+
77
+
efi_bs_call(free_pool, memory_map);
78
+
79
+
return ret;
47
80
}
48
81
49
82
efi_status_t handle_kernel_image(unsigned long *image_addr,
···
88
55
efi_status_t status;
89
56
unsigned long kernel_size, kernel_memsize = 0;
90
57
u32 phys_seed = 0;
58
+
59
+
/*
60
+
* Although relocatable kernels can fix up the misalignment with
61
+
* respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are
62
+
* subtly out of sync with those recorded in the vmlinux when kaslr is
63
+
* disabled but the image required relocation anyway. Therefore retain
64
+
* 2M alignment if KASLR was explicitly disabled, even if it was not
65
+
* going to be activated to begin with.
66
+
*/
67
+
u64 min_kimg_align = efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
91
68
92
69
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
93
70
if (!efi_nokaslr) {
···
119
76
if (image->image_base != _text)
120
77
efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
121
78
79
+
if (!IS_ALIGNED((u64)_text, EFI_KIMG_ALIGN))
80
+
efi_err("FIRMWARE BUG: kernel image not aligned on %ldk boundary\n",
81
+
EFI_KIMG_ALIGN >> 10);
82
+
122
83
kernel_size = _edata - _text;
123
84
kernel_memsize = kernel_size + (_end - _edata);
124
85
*reserve_size = kernel_memsize;
···
132
85
* If KASLR is enabled, and we have some randomness available,
133
86
* locate the kernel at a randomized offset in physical memory.
134
87
*/
135
-
status = efi_random_alloc(*reserve_size, min_kimg_align(),
88
+
status = efi_random_alloc(*reserve_size, min_kimg_align,
136
89
reserve_addr, phys_seed);
90
+
if (status != EFI_SUCCESS)
91
+
efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
137
92
} else {
138
93
status = EFI_OUT_OF_RESOURCES;
139
94
}
140
95
141
96
if (status != EFI_SUCCESS) {
142
-
if (IS_ALIGNED((u64)_text, min_kimg_align())) {
97
+
if (!check_image_region((u64)_text, kernel_memsize)) {
98
+
efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
99
+
} else if (IS_ALIGNED((u64)_text, min_kimg_align)) {
143
100
/*
144
101
* Just execute from wherever we were loaded by the
145
102
* UEFI PE/COFF loader if the alignment is suitable.
···
154
103
}
155
104
156
105
status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
157
-
ULONG_MAX, min_kimg_align());
106
+
ULONG_MAX, min_kimg_align);
158
107
159
108
if (status != EFI_SUCCESS) {
160
109
efi_err("Failed to relocate kernel\n");
+2
drivers/firmware/efi/libstub/randomalloc.c
+2
drivers/firmware/efi/libstub/randomalloc.c