[PATCH] lib/decompressors: Use real out buf size for gunzip with kernel
From: Yinghai Lu
Date: Thu Aug 13 2015 - 03:26:46 EST
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.
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Fixes: 1431574a1c4 (lib/decompressors: fix "no limit" output buffer length)
Cc: Alexandre Courbot <acourbot@xxxxxxxxxx>
Cc: Jon Medhurst <tixy@xxxxxxxxxx>
Cc: Stephen Warren <swarren@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
---
arch/x86/boot/compressed/misc.c | 3 ++-
lib/decompress_bunzip2.c | 9 +++++++++
lib/decompress_inflate.c | 40 +++++++++++++++++++++++++++++++++++-----
lib/decompress_unlz4.c | 10 ++++++++++
lib/decompress_unlzma.c | 10 ++++++++++
lib/decompress_unlzo.c | 22 +++++++++++++++++++++-
lib/decompress_unxz.c | 21 ++++++++++++++++++++-
7 files changed, 107 insertions(+), 8 deletions(-)
Index: linux-2.6/arch/x86/boot/compressed/misc.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.c
+++ linux-2.6/arch/x86/boot/compressed/misc.c
@@ -448,7 +448,8 @@ 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
Index: linux-2.6/lib/decompress_bunzip2.c
===================================================================
--- linux-2.6.orig/lib/decompress_bunzip2.c
+++ linux-2.6/lib/decompress_bunzip2.c
@@ -752,4 +752,13 @@ STATIC int INIT decompress(unsigned char
{
return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
}
+STATIC int INIT __decompress(unsigned char *buf, long len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *outbuf, long olen,
+ long *pos,
+ void (*error)(char *x))
+{
+ return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
+}
#endif
Index: linux-2.6/lib/decompress_inflate.c
===================================================================
--- linux-2.6.orig/lib/decompress_inflate.c
+++ linux-2.6/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 +182,33 @@ gunzip_nomem1:
return rc; /* returns Z_OK (0) if successful */
}
-#define decompress gunzip
+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);
+}
+
+#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 *pos,
+ void (*error)(char *x))
+{
+ return gunzip(buf, len, fill, flush, out_buf, pos, error);
+}
+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
Index: linux-2.6/lib/decompress_unlz4.c
===================================================================
--- linux-2.6.orig/lib/decompress_unlz4.c
+++ linux-2.6/lib/decompress_unlz4.c
@@ -206,4 +206,14 @@ STATIC int INIT decompress(unsigned char
{
return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
}
+STATIC int INIT __decompress(unsigned char *buf, long in_len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *output, long out_len,
+ long *posp,
+ void (*error)(char *x)
+ )
+{
+ return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
+}
#endif
Index: linux-2.6/lib/decompress_unlzma.c
===================================================================
--- linux-2.6.orig/lib/decompress_unlzma.c
+++ linux-2.6/lib/decompress_unlzma.c
@@ -677,4 +677,14 @@ STATIC int INIT decompress(unsigned char
{
return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
}
+STATIC int INIT __decompress(unsigned char *buf, long in_len,
+ long (*fill)(void*, unsigned long),
+ long (*flush)(void*, unsigned long),
+ unsigned char *output, long out_len,
+ long *posp,
+ void (*error)(char *x)
+ )
+{
+ return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
+}
#endif
Index: linux-2.6/lib/decompress_unlzo.c
===================================================================
--- linux-2.6.orig/lib/decompress_unlzo.c
+++ linux-2.6/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 +288,23 @@ 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 *pos,
+ void (*error)(char *x))
+{
+ return unlzo(buf, len, fill, flush, out_buf, pos, error);
+}
+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
Index: linux-2.6/lib/decompress_unxz.c
===================================================================
--- linux-2.6.orig/lib/decompress_unxz.c
+++ linux-2.6/lib/decompress_unxz.c
@@ -394,4 +394,23 @@ 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 *pos,
+ void (*error)(char *x))
+{
+ return unxz(buf, len, fill, flush, out_buf, pos, error);
+}
+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
--
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