Messages in this thread Patch in this message | | | Subject | [PATCH 3/5] x86: simplify early command line parsing | From | Dave Hansen <> | Date | Tue, 22 Dec 2015 14:52:41 -0800 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
__cmdline_find_option_bool() tries to account for both NULL-terminated and non-NULL-terminated strings. It keeps 'pos' to look for the end of the buffer and also looks for '!c' in a bunch of places to look for NULL termination.
But, it also calls strlen(). You can't call strlen on a non-NULL-terminated string.
If !strlen(cmdline), then cmdline[0]=='\0'. In that case, we will go in to the while() loop, set c='\0', hit st_wordstart, notice !c, and will immediately return 0.
So, remove the strlen(). It is unnecessary and unsafe.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: linux-kernel@vger.kernel.org Cc: fenghua.yu@intel.com Cc: yu-cheng.yu@intel.com ---
b/arch/x86/lib/cmdline.c | 3 --- 1 file changed, 3 deletions(-)
diff -puN arch/x86/lib/cmdline.c~x86-early-command-line-non-term arch/x86/lib/cmdline.c --- a/arch/x86/lib/cmdline.c~x86-early-command-line-non-term 2015-12-22 11:56:59.454186167 -0800 +++ b/arch/x86/lib/cmdline.c 2015-12-22 11:56:59.457186302 -0800 @@ -39,9 +39,6 @@ int cmdline_find_option_bool(const char if (!cmdline) return -1; /* No command line */ - if (!strlen(cmdline)) - return 0; - /* * This 'pos' check ensures we do not overrun * a non-NULL-terminated 'cmdline' _
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