From 352f2c9a570d38bced287a273e79dccae7c5ef41 Mon Sep 17 00:00:00 2001 From: Aurelien Aptel Date: Mon, 16 Sep 2019 05:45:42 +0200 Subject: cifs: cifsroot: add more err checking make cifs more verbose about buffer size errors and add some comments Signed-off-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/cifsroot.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/cifs/cifsroot.c b/fs/cifs/cifsroot.c index 8760d9cbf25e..37edbfb8e096 100644 --- a/fs/cifs/cifsroot.c +++ b/fs/cifs/cifsroot.c @@ -24,6 +24,7 @@ static char root_opts[1024] __initdata = DEFAULT_MNT_OPTS; static __be32 __init parse_srvaddr(char *start, char *end) { + /* TODO: ipv6 support */ char addr[sizeof("aaa.bbb.ccc.ddd")]; int i = 0; @@ -50,14 +51,24 @@ static int __init cifs_root_setup(char *line) if (!s || s[1] == '\0') return 1; + /* make s point to ',' or '\0' at end of line */ s = strchrnul(s, ','); + /* len is strlen(unc) + '\0' */ len = s - line + 1; - if (len <= sizeof(root_dev)) { - strlcpy(root_dev, line, len); - srvaddr = parse_srvaddr(&line[2], s); - if (*s) { - snprintf(root_opts, sizeof(root_opts), "%s,%s", + if (len > sizeof(root_dev)) { + printk(KERN_ERR "Root-CIFS: UNC path too long\n"); + return 1; + } + strlcpy(root_dev, line, len); + srvaddr = parse_srvaddr(&line[2], s); + if (*s) { + int n = snprintf(root_opts, + sizeof(root_opts), "%s,%s", DEFAULT_MNT_OPTS, s + 1); + if (n >= sizeof(root_opts)) { + printk(KERN_ERR "Root-CIFS: mount options string too long\n"); + root_opts[sizeof(root_opts)-1] = '\0'; + return 1; } } } -- cgit