From 3528a95322b5c1ce882ab723f175a1845430cd89 Mon Sep 17 00:00:00 2001 From: Cory Olmo Date: Fri, 29 Sep 2006 01:58:44 -0700 Subject: [PATCH] [PATCH] SELinux: support mls categories for context mounts Allows commas to be embedded into context mount options (i.e. "-o context=some_selinux_context_t"), to better support multiple categories, which are separated by commas and confuse mount. For example, with the current code: mount -t iso9660 /dev/cdrom /media/cdrom -o \ ro,context=system_u:object_r:iso9660_t:s0:c1,c3,c4,exec The context option that will be interpreted by SELinux is context=system_u:object_r:iso9660_t:s0:c1 instead of context=system_u:object_r:iso9660_t:s0:c1,c3,c4 The options that will be passed on to the file system will be ro,c3,c4,exec. The proposed solution is to allow/require the SELinux context option specified to mount to use quotes when the context contains a comma. This patch modifies the option parsing in parse_opts(), contained in mount.c, to take options after finding a comma only if it hasn't seen a quote or if the quotes are matched. It also introduces a new function that will strip the quotes from the context option prior to translation. The quotes are replaced after the translation is completed to insure that in the event the raw context contains commas the kernel will be able to interpret the correct context. Signed-off-by: Cory Olmo Signed-off-by: James Morris Acked-by: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index e4d81a42fca4..cac0273ec447 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -398,7 +398,7 @@ static int try_context_mount(struct super_block *sb, void *data) /* Standard string-based options. */ char *p, *options = data; - while ((p = strsep(&options, ",")) != NULL) { + while ((p = strsep(&options, "|")) != NULL) { int token; substring_t args[MAX_OPT_ARGS]; @@ -1923,18 +1923,40 @@ static inline void take_option(char **to, char *from, int *first, int len) if (!*first) { **to = ','; *to += 1; - } - else + } else *first = 0; memcpy(*to, from, len); *to += len; } +static inline void take_selinux_option(char **to, char *from, int *first, + int len) +{ + int current_size = 0; + + if (!*first) { + **to = '|'; + *to += 1; + } + else + *first = 0; + + while (current_size < len) { + if (*from != '"') { + **to = *from; + *to += 1; + } + from += 1; + current_size += 1; + } +} + static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy) { int fnosec, fsec, rc = 0; char *in_save, *in_curr, *in_end; char *sec_curr, *nosec_save, *nosec; + int open_quote = 0; in_curr = orig; sec_curr = copy; @@ -1956,11 +1978,14 @@ static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void in_save = in_end = orig; do { - if (*in_end == ',' || *in_end == '\0') { + if (*in_end == '"') + open_quote = !open_quote; + if ((*in_end == ',' && open_quote == 0) || + *in_end == '\0') { int len = in_end - in_curr; if (selinux_option(in_curr, len)) - take_option(&sec_curr, in_curr, &fsec, len); + take_selinux_option(&sec_curr, in_curr, &fsec, len); else take_option(&nosec, in_curr, &fnosec, len); -- 2.30.2