Attachment 1452455 Details for Bug 1592148 – Patch to move DEFAULT_LOADER_CHAR into writable data section

[patch] Patch to move DEFAULT_LOADER_CHAR into writable data section

0001-Fix-attempted-write-to-a-string-literal.patch (text/plain), 2.56 KB, created by Mark Salter on 2018-06-17 21:27:17 UTC

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Creator: Mark Salter

Created: 2018-06-17 21:27:17 UTC

Size: 2.56 KB

patch

obsolete

>From 3a95f63bcd574b4555d9487d6718267f40ffc87c Mon Sep 17 00:00:00 2001
>From: Mark Salter <msalter@redhat.com>
>Date: Sun, 17 Jun 2018 00:13:12 -0400
>Subject: [PATCH] Fix attempted write to a string literal
>
>Newer versions of edk2 mark text sections read-only. This uncovers
>a problem where shim code tries to write to a string literal. This
>now leads to a permission fault when translate_slashes is called
>to work on DEFAULT_LOADER_CHAR. So put DEFAULT_LOADER_CHAR into
>.data to avoid the problem.
>
>Signed-off-by: Mark Salter <msalter@redhat.com>
>---
> httpboot.c | 2 +-
> netboot.c  | 4 ++--
> shim.c     | 2 ++
> shim.h     | 2 ++
> 4 files changed, 7 insertions(+), 3 deletions(-)
>
>diff --git a/httpboot.c b/httpboot.c
>index 4cfa3aa..e9743be 100644
>--- a/httpboot.c
>+++ b/httpboot.c
>@@ -695,7 +695,7 @@ httpboot_fetch_buffer (EFI_HANDLE image, VOID **buffer, UINT64 *buf_size)
> 	if (!uri)
> 		return EFI_NOT_READY;
> 
>-	next_loader = translate_slashes(DEFAULT_LOADER_CHAR);
>+	next_loader = translate_slashes(default_loader_char);
> 
> 	/* Create the URI for the next loader based on the original URI */
> 	efi_status = generate_next_uri(uri, next_loader, &next_uri);
>diff --git a/netboot.c b/netboot.c
>index 58babfb..d8436dd 100644
>--- a/netboot.c
>+++ b/netboot.c
>@@ -189,7 +189,7 @@ static BOOLEAN extract_tftp_info(CHAR8 *url)
> 	CHAR8 *start, *end;
> 	CHAR8 ip6str[40];
> 	CHAR8 ip6inv[16];
>-	CHAR8 *template = (CHAR8 *)translate_slashes(DEFAULT_LOADER_CHAR);
>+	CHAR8 *template = (CHAR8 *)translate_slashes(default_loader_char);
> 
> 	// to check against str2ip6() errors
> 	memset(ip6inv, 0, sizeof(ip6inv));
>@@ -254,7 +254,7 @@ static EFI_STATUS parseDhcp6()
> 
> static EFI_STATUS parseDhcp4()
> {
>-	CHAR8 *template = (CHAR8 *)translate_slashes(DEFAULT_LOADER_CHAR);
>+	CHAR8 *template = (CHAR8 *)translate_slashes(default_loader_char);
> 	INTN template_len = strlen(template) + 1;
> 	EFI_PXE_BASE_CODE_DHCPV4_PACKET* pkt_v4 = (EFI_PXE_BASE_CODE_DHCPV4_PACKET *)&pxe->Mode->DhcpAck.Dhcpv4;
> 
>diff --git a/shim.c b/shim.c
>index 0015534..8be41d3 100644
>--- a/shim.c
>+++ b/shim.c
>@@ -76,6 +76,8 @@ UINT32 vendor_dbx_size;
> UINT8 *vendor_cert;
> UINT8 *vendor_dbx;
> 
>+char default_loader_char[] = DEFAULT_LOADER_CHAR;
>+
> /*
>  * indicator of how an image has been verified
>  */
>diff --git a/shim.h b/shim.h
>index a25a660..36b1085 100644
>--- a/shim.h
>+++ b/shim.h
>@@ -175,6 +175,8 @@ extern UINT8 user_insecure_mode;
> extern UINT8 ignore_db;
> extern UINT8 in_protocol;
> 
>+extern char default_loader_char[];
>+
> #define perror_(file, line, func, fmt, ...) ({					\
> 		UINTN __perror_ret = 0;						\
> 		if (!in_protocol)						\
>-- 
>2.18.0.rc2
>

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Attachments on bug 1592148: 1452455