From 69ac43b05eef4b8555e84ad51ceb6c58b5a3bc75 Mon Sep 17 00:00:00 2001 From: Chen Liu Date: Wed, 23 Mar 2011 10:14:58 +0100 Subject: [PATCH] [S390] early: Fix possible overlapping data buffer This patch fixed bugzilla #12965: https://bugzilla.kernel.org/show_bug.cgi?id=12965 The original code contains some inproper use of sprintf function where a buffer is used both as input string as well as output string. It should remember the written bytes in the previous and use that as the offset for later writing. Also replace sprintf with snprintf. Signed-off-by: Chen Liu Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/early.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index 3b7e7dddc324..668138ee85d9 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -94,6 +94,7 @@ static noinline __init void create_kernel_nss(void) unsigned int sinitrd_pfn, einitrd_pfn; #endif int response; + int hlen; size_t len; char *savesys_ptr; char defsys_cmd[DEFSYS_CMD_SIZE]; @@ -124,22 +125,24 @@ static noinline __init void create_kernel_nss(void) end_pfn = PFN_UP(__pa(&_end)); min_size = end_pfn << 2; - sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X", - kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1, - eshared_pfn, end_pfn); + hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE, + "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X", + kernel_nss_name, stext_pfn - 1, stext_pfn, + eshared_pfn - 1, eshared_pfn, end_pfn); #ifdef CONFIG_BLK_DEV_INITRD if (INITRD_START && INITRD_SIZE) { sinitrd_pfn = PFN_DOWN(__pa(INITRD_START)); einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE)); min_size = einitrd_pfn << 2; - sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd, - sinitrd_pfn, einitrd_pfn); + hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen, + " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn); } #endif - sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13", - defsys_cmd, min_size); + snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen, + " EW MINSIZE=%.7iK PARMREGS=0-13", min_size); + defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0'; sprintf(savesys_cmd, "SAVESYS %s \n IPL %s", kernel_nss_name, kernel_nss_name); -- 2.20.1