From: Chen Gang Date: Sat, 22 Jun 2013 05:26:09 +0000 Subject: [PATCH] arch: sparc: kernel: check the memory length before use strcpy(). Message-Id: <51C53571.9070403@asianux.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sam Ravnborg , zhaohongjiang@huawei.com Cc: David Miller , Greg KH , sparclinux@vger.kernel.org, "linux-kernel@vger.kernel.org" , Linux-Arch For the related next strcpy(), the destination length is less than 512, but the source maximize length may be 'OPROMMAXPARAM' (4096) which is more than 512. One work flow may: openprom_sunos_ioctl() -> if (cmd = OPROMSETOPT) getstrings() -> will alloc buffer with size 'OPROMMAXPARAM'. opromsetopt() -> devide the buffer into 'var' and 'value' of_set_property() -> pass prom_setprop() -> pass ldom_set_var() And do not mind the additional 4 alignment buffer increasing, since 'sizeof(pkt) - sizeof(pkt.header)' is 4 alignment at least. Signed-off-by: Chen Gang --- arch/sparc/kernel/ds.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/sparc/kernel/ds.c b/arch/sparc/kernel/ds.c index 5ef48da..11d460f 100644 --- a/arch/sparc/kernel/ds.c +++ b/arch/sparc/kernel/ds.c @@ -783,6 +783,16 @@ void ldom_set_var(const char *var, const char *value) char *base, *p; int msg_len, loops; + if (strlen(var) + strlen(value) + 2 > + sizeof(pkt) - sizeof(pkt.header)) { + printk(KERN_ERR PFX + "contents length: %zu, which more than max: %lu," + "so could not set (%s) variable to (%s).\n", + strlen(var) + strlen(value) + 2, + sizeof(pkt) - sizeof(pkt.header), var, value); + return; + } + memset(&pkt, 0, sizeof(pkt)); pkt.header.data.tag.type = DS_DATA; pkt.header.data.handle = cp->handle; -- 1.7.11.7