lib/decompressors: use real out buf size for gunzip with kernel

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>

7 files changed, 11 insertions, 9 deletions

diff --git a/arch/arm/boot/compressed/decompress.c b/arch/arm/boot/compressed/decompress.c
index bd245d34952d..a0765e7ed6c7 100644
--- a/arch/arm/boot/compressed/decompress.c
+++ b/arch/arm/boot/compressed/decompress.c
@@ -57,5 +57,5 @@ extern char * strstr(const char * s1, const char *s2);
 
 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);
 }
diff --git a/arch/m32r/boot/compressed/misc.c b/arch/m32r/boot/compressed/misc.c
index 28a09529f206..3a7692745868 100644
--- a/arch/m32r/boot/compressed/misc.c
+++ b/arch/m32r/boot/compressed/misc.c
@@ -86,6 +86,7 @@ decompress_kernel(int mmu_on, unsigned char *zimage_data,
 	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");
 }
diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
index 54831069a206..080cd53bac36 100644
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -111,8 +111,8 @@ void decompress_kernel(unsigned long boot_heap_start)
 	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");
diff --git a/arch/s390/boot/compressed/misc.c b/arch/s390/boot/compressed/misc.c
index 42506b371b74..4da604ebf6fd 100644
--- 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;
 }
diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c
index 95470a472d2c..208a9753ab38 100644
--- 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");
 }
diff --git a/arch/unicore32/boot/compressed/misc.c b/arch/unicore32/boot/compressed/misc.c
index 176d5bda3559..5c65dfee278c 100644
--- a/arch/unicore32/boot/compressed/misc.c
+++ b/arch/unicore32/boot/compressed/misc.c
@@ -119,8 +119,8 @@ unsigned long decompress_kernel(unsigned long output_start,
 	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;
 }
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index a107b935e22f..e28437e0f708 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -424,7 +424,8 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
 #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