[PATCH 4.2 133/134] lib/decompressors: use real out buf size for gunzip with kernel

Greg Kroah-Hartman
2015-09-26T21:54:11Z

From: Yinghai Lu <yinghai@kernel.org>

commit 2d3862d26e67a59340ba1cf1748196c76c5787de upstream.

When loading x86 64bit kernel above 4GiB with patched grub2, got kernel
gunzip error.

| early console in decompress_kernel
| decompress_kernel:
| input: [0x807f2143b4-0x807ff61aee]
| output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len
| boot via startup_64
| KASLR using RDTSC...
| new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size
| decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee]
|
| Decompressing Linux... gz...
|
| uncompression error
|
| -- System halted

the new buffer is at 0x46fe000000ULL, decompressor_gzip is using
0xffffffb901ffffff as out_len. gunzip in lib/zlib_inflate/inflate.c cap
that len to 0x01ffffff and decompress fails later.

We could hit this problem with crashkernel booting that uses kexec loading
kernel above 4GiB.

We have decompress_* support:
1. inbuf[]/outbuf[] for kernel preboot.
2. inbuf[]/flush() for initramfs
3. fill()/flush() for initrd.
This bug only affect kernel preboot path that use outbuf[].

Add __decompress and take real out_buf_len for gunzip instead of guessing
wrong buf size.

Fixes: 1431574a1c4 (lib/decompressors: fix "no limit" output buffer length)
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Jon Medhurst <tixy@linaro.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm/boot/compressed/decompress.c | 2 +-
arch/h8300/boot/compressed/misc.c | 2 +-
arch/m32r/boot/compressed/misc.c | 3 ++-
arch/mips/boot/compressed/decompress.c | 4 ++--
arch/s390/boot/compressed/misc.c | 2 +-
arch/sh/boot/compressed/misc.c | 2 +-
arch/unicore32/boot/compressed/misc.c | 4 ++--
arch/x86/boot/compressed/misc.c | 3 ++-
lib/decompress_bunzip2.c | 6 +++---
lib/decompress_inflate.c | 31 ++++++++++++++++++++++++++-----
lib/decompress_unlz4.c | 6 +++---
lib/decompress_unlzma.c | 7 +++----
lib/decompress_unlzo.c | 13 ++++++++++++-
lib/decompress_unxz.c | 12 +++++++++++-
14 files changed, 70 insertions(+), 27 deletions(-)

--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -57,5 +57,5 @@ extern char * strstr(const char * s1, co

int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x))
{
- return decompress(input, len, NULL, NULL, output, NULL, error);
+ return __decompress(input, len, NULL, NULL, output, 0, NULL, error);
}
--- a/arch/h8300/boot/compressed/misc.c
+++ b/arch/h8300/boot/compressed/misc.c
@@ -70,5 +70,5 @@ void decompress_kernel(void)
free_mem_ptr = (unsigned long)&_end;
free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;

- decompress(input_data, input_len, NULL, NULL, output, NULL, error);
+ __decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
}
--- a/arch/m32r/boot/compressed/misc.c
+++ b/arch/m32r/boot/compressed/misc.c
@@ -86,6 +86,7 @@ decompress_kernel(int mmu_on, unsigned c
free_mem_end_ptr = free_mem_ptr + BOOT_HEAP_SIZE;

puts("\nDecompressing Linux... ");
- decompress(input_data, input_len, NULL, NULL, output_data, NULL, error);
+ __decompress(input_data, input_len, NULL, NULL, output_data, 0,
+ NULL, error);
puts("done.\nBooting the kernel.\n");
}
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -111,8 +111,8 @@ void decompress_kernel(unsigned long boo
puts("\n");

/* Decompress the kernel with according algorithm */
- decompress((char *)zimage_start, zimage_size, 0, 0,
- (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, error);
+ __decompress((char *)zimage_start, zimage_size, 0, 0,
+ (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);

/* FIXME: should we flush cache here? */
puts("Now, booting the kernel...\n");
--- a/arch/s390/boot/compressed/misc.c
+++ b/arch/s390/boot/compressed/misc.c
@@ -167,7 +167,7 @@ unsigned long decompress_kernel(void)
#endif

puts("Uncompressing Linux... ");
- decompress(input_data, input_len, NULL, NULL, output, NULL, error);
+ __decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
puts("Ok, booting the kernel.\n");
return (unsigned long) output;
}
--- a/arch/sh/boot/compressed/misc.c
+++ b/arch/sh/boot/compressed/misc.c
@@ -132,7 +132,7 @@ void decompress_kernel(void)

puts("Uncompressing Linux... ");
cache_control(CACHE_ENABLE);
- decompress(input_data, input_len, NULL, NULL, output, NULL, error);
+ __decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
cache_control(CACHE_DISABLE);
puts("Ok, booting the kernel.\n");
}
--- a/arch/unicore32/boot/compressed/misc.c
+++ b/arch/unicore32/boot/compressed/misc.c
@@ -119,8 +119,8 @@ unsigned long decompress_kernel(unsigned
output_ptr = get_unaligned_le32(tmp);

arch_decomp_puts("Uncompressing Linux...");
- decompress(input_data, input_data_end - input_data, NULL, NULL,
- output_data, NULL, error);
+ __decompress(input_data, input_data_end - input_data, NULL, NULL,
+ output_data, 0, NULL, error);
arch_decomp_puts(" done, booting the kernel.\n");
return output_ptr;
}
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -424,7 +424,8 @@ asmlinkage __visible void *decompress_ke
#endif

debug_putstr("\nDecompressing Linux... ");
- decompress(input_data, input_len, NULL, NULL, output, NULL, error);
+ __decompress(input_data, input_len, NULL, NULL, output, output_len,
+ NULL, error);
parse_elf(output);
/*
* 32-bit always performs relocations. 64-bit relocations are only
--- a/lib/decompress_bunzip2.c
+++ b/lib/decompress_bunzip2.c
@@ -743,12 +743,12 @@ exit_0:
}

#ifdef PREBOOT
-STATIC int INIT decompress(unsigned char *buf, long len,
+STATIC int INIT __decompress(unsigned char *buf, long len,
long (*fill)(void*, unsigned long),
long (*flush)(void*, unsigned long),
- unsigned char *outbuf,
+ unsigned char *outbuf, long olen,
long *pos,
- void(*error)(char *x))
+ void (*error)(char *x))
{
return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
}
--- a/lib/decompress_inflate.c
+++ b/lib/decompress_inflate.c
@@ -1,4 +1,5 @@
#ifdef STATIC
+#define PREBOOT
/* Pre-boot environment: included */

/* prevent inclusion of _LINUX_KERNEL_H in pre-boot environment: lots
@@ -33,23 +34,23 @@ static long INIT nofill(void *buffer, un
}

/* Included from initramfs et al code */
-STATIC int INIT gunzip(unsigned char *buf, long len,
+STATIC int INIT __gunzip(unsigned char *buf, long len,
long (*fill)(void*, unsigned long),
long (*flush)(void*, unsigned long),
- unsigned char *out_buf,
+ unsigned char *out_buf, long out_len,
long *pos,
void(*error)(char *x)) {
u8 *zbuf;
struct z_stream_s *strm;
int rc;
- size_t out_len;

rc = -1;
if (flush) {
out_len = 0x8000; /* 32 K */
out_buf = malloc(out_len);
} else {
- out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
+ if (!out_len)
+ out_len = ((size_t)~0) - (size_t)out_buf; /* no limit */
}
if (!out_buf) {
error("Out of memory while allocating output buffer");
@@ -181,4 +182,24 @@ gunzip_nomem1:
return rc; /* returns Z_OK (0) if successful */
}

-#define decompress gunzip
+#ifndef PREBOOT
+STATIC int INIT gunzip(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *out_buf,
+ long *pos,
+ void (*error)(char *x))
+{
+ return __gunzip(buf, len, fill, flush, out_buf, 0, pos, error);
+}
+#else
+STATIC int INIT __decompress(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *out_buf, long out_len,
+ long *pos,
+ void (*error)(char *x))
+{
+ return __gunzip(buf, len, fill, flush, out_buf, out_len, pos, error);
+}
+#endif
--- a/lib/decompress_unlz4.c
+++ b/lib/decompress_unlz4.c
@@ -196,12 +196,12 @@ exit_0:
}

#ifdef PREBOOT
-STATIC int INIT decompress(unsigned char *buf, long in_len,
+STATIC int INIT __decompress(unsigned char *buf, long in_len,
long (*fill)(void*, unsigned long),
long (*flush)(void*, unsigned long),
- unsigned char *output,
+ unsigned char *output, long out_len,
long *posp,
- void(*error)(char *x)
+ void (*error)(char *x)
)
{
return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
--- a/lib/decompress_unlzma.c
+++ b/lib/decompress_unlzma.c
@@ -667,13 +667,12 @@ exit_0:
}

#ifdef PREBOOT
-STATIC int INIT decompress(unsigned char *buf, long in_len,
+STATIC int INIT __decompress(unsigned char *buf, long in_len,
long (*fill)(void*, unsigned long),
long (*flush)(void*, unsigned long),
- unsigned char *output,
+ unsigned char *output, long out_len,
long *posp,
- void(*error)(char *x)
- )
+ void (*error)(char *x))
{
return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
}
--- a/lib/decompress_unlzo.c
+++ b/lib/decompress_unlzo.c
@@ -31,6 +31,7 @@
*/

#ifdef STATIC
+#define PREBOOT
#include "lzo/lzo1x_decompress_safe.c"
#else
#include <linux/decompress/unlzo.h>
@@ -287,4 +288,14 @@ exit:
return ret;
}

-#define decompress unlzo
+#ifdef PREBOOT
+STATIC int INIT __decompress(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *out_buf, long olen,
+ long *pos,
+ void (*error)(char *x))
+{
+ return unlzo(buf, len, fill, flush, out_buf, pos, error);
+}
+#endif
--- a/lib/decompress_unxz.c
+++ b/lib/decompress_unxz.c
@@ -394,4 +394,14 @@ error_alloc_state:
* This macro is used by architecture-specific files to decompress
* the kernel image.
*/
-#define decompress unxz
+#ifdef XZ_PREBOOT
+STATIC int INIT __decompress(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *out_buf, long olen,
+ long *pos,
+ void (*error)(char *x))
+{
+ return unxz(buf, len, fill, flush, out_buf, pos, error);
+}
+#endif