With the (long ago) interface change to have the secid_to_secctx functions do the string allocation instead of having the caller do the allocation we lost the ability to query the security server for the length of the upcoming string. The SECMARK code would like to allocate a netlink skb with enough length to hold the string but it is just too unclean to do the string allocation twice or to do the allocation the first time and hold onto the string and slen. This patch adds the ability to call security_secid_to_secctx() with a NULL data pointer and it will just set the slen pointer. Signed-off-by: Eric Paris <eparis@xxxxxxxxxx> --- security/selinux/ss/services.c | 11 +++++++++-- security/smack/smack_lsm.c | 3 ++- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 73508af..1d4955a 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -998,7 +998,8 @@ static int context_struct_to_string(struct context *context, char **scontext, u3 { char *scontextp; - *scontext = NULL; + if (scontext) + *scontext = NULL; *scontext_len = 0; if (context->len) { @@ -1015,6 +1016,9 @@ static int context_struct_to_string(struct context *context, char **scontext, u3 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; *scontext_len += mls_compute_context_len(context); + if (!scontext) + return 0; + /* Allocate space for the context; caller must free this space. */ scontextp = kmalloc(*scontext_len, GFP_ATOMIC); if (!scontextp) @@ -1054,7 +1058,8 @@ static int security_sid_to_context_core(u32 sid, char **scontext, struct context *context; int rc = 0; - *scontext = NULL; + if (scontext) + *scontext = NULL; *scontext_len = 0; if (!ss_initialized) { @@ -1062,6 +1067,8 @@ static int security_sid_to_context_core(u32 sid, char **scontext, char *scontextp; *scontext_len = strlen(initial_sid_to_string[sid]) + 1; + if (!scontext) + goto out; scontextp = kmalloc(*scontext_len, GFP_ATOMIC); if (!scontextp) { rc = -ENOMEM; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index c448d57..b95d7b1 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3005,7 +3005,8 @@ static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { char *sp = smack_from_secid(secid); - *secdata = sp; + if (secdata) + *secdata = sp; *seclen = strlen(sp); return 0; } -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html