[syslinux:master] com32/lib/syslinux/load_linux.c: update prot_mode_base

syslinux-bot for Gene Cumm gene.cumm at gmail.com
Sat Apr 18 04:15:06 PDT 2015

Commit-ID:  1de437de4c6ab1bab48e92bcaf5baa946eba389b
Gitweb:     http://www.syslinux.org/commit/1de437de4c6ab1bab48e92bcaf5baa946eba389b
Author:     Gene Cumm <gene.cumm at gmail.com>
AuthorDate: Sat, 18 Apr 2015 07:11:07 -0400
Committer:  Gene Cumm <gene.cumm at gmail.com>
CommitDate: Sat, 18 Apr 2015 07:11:07 -0400

com32/lib/syslinux/load_linux.c: update prot_mode_base

If the kernel is relocatable and the protected mode code will not fit
in the initially determined location, that code will be moved to the
next available location. However, beginning with commit 8f470e7b, the
code is moved to the initially determined location instead of the next
available location because prot_mode_base is no longer updated to the
correct location. Since whdr->code32_start is updated, it is pointing
to the wrong execution start location, random code is executed and
the machine is rebooted.

Restore the old behavior by assigning prot_mode_base the value of
base. Tested on a machine that exposed this behavior.

Signed-off-by: Scot Doyle <lkml14 at scotdoyle.com>
Signed-off-by: Gene Cumm <gene.cumm at gmail.com>

 com32/lib/syslinux/load_linux.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/com32/lib/syslinux/load_linux.c b/com32/lib/syslinux/load_linux.c
index ac73729..fc7f04f 100644
--- a/com32/lib/syslinux/load_linux.c
+++ b/com32/lib/syslinux/load_linux.c
@@ -323,6 +323,7 @@ int bios_boot_linux(void *kernel_buf, size_t kernel_size,
     whdr->code32_start += base - prot_mode_base;
+    prot_mode_base = base;
     /* Real mode code */
     if (syslinux_memmap_find(amap, &real_mode_base,

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