From: Jo-Philipp Wich Date: Mon, 15 Aug 2016 10:14:50 +0000 (+0200) Subject: kernel: fix crashlog on x86/64 X-Git-Tag: v17.01.0-rc1~1720 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=d9345bc5bf8063ce433c0152893f93000fb0ddfb;p=oweals%2Fopenwrt.git kernel: fix crashlog on x86/64 The bootmem area reserved for crashlog might be smaller than CRASHLOG_OFFSET bytes, leading to an integer underflow when calculating the memory address in crashlog_set_addr() which subsequently causes the kernel to crash when attempting to vmap() the crashlog pages. Change the logic to only consider the offset when the size of the used memory area is sufficient. Signed-off-by: Jo-Philipp Wich --- diff --git a/target/linux/generic/patches-4.4/930-crashlog.patch b/target/linux/generic/patches-4.4/930-crashlog.patch index bb97c90196..fdc80d750a 100644 --- a/target/linux/generic/patches-4.4/930-crashlog.patch +++ b/target/linux/generic/patches-4.4/930-crashlog.patch @@ -43,7 +43,7 @@ --- /dev/null +++ b/kernel/crashlog.c -@@ -0,0 +1,209 @@ +@@ -0,0 +1,213 @@ +/* + * Crash information logger + * Copyright (C) 2010 Felix Fietkau @@ -117,7 +117,11 @@ + if (addr + size > limit) + size = limit - addr; + -+ crashlog_addr = addr + size - CRASHLOG_OFFSET; ++ crashlog_addr = addr; ++ ++ if (addr + size > CRASHLOG_OFFSET) ++ crashlog_addr += size - CRASHLOG_OFFSET; ++ + return true; +} +