From 0fa104726b6cc7b1ebb4c60d55cb6abda745f4b6 Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Tue, 4 Jul 2017 15:53:13 +0300 Subject: [PATCH] net, sunrpc: convert gss_cl_ctx.count from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- include/linux/sunrpc/auth_gss.h | 3 ++- net/sunrpc/auth_gss/auth_gss.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/linux/sunrpc/auth_gss.h b/include/linux/sunrpc/auth_gss.h index 36eebc451b41..cebdf8745901 100644 --- a/include/linux/sunrpc/auth_gss.h +++ b/include/linux/sunrpc/auth_gss.h @@ -13,6 +13,7 @@ #define _LINUX_SUNRPC_AUTH_GSS_H #ifdef __KERNEL__ +#include #include #include #include @@ -65,7 +66,7 @@ struct rpc_gss_init_res { * the wire when communicating with a server. */ struct gss_cl_ctx { - atomic_t count; + refcount_t count; enum rpc_gss_proc gc_proc; u32 gc_seq; spinlock_t gc_seq_lock; diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index 4f16953e4954..72f129c74acd 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -117,14 +117,14 @@ static const struct rpc_pipe_ops gss_upcall_ops_v1; static inline struct gss_cl_ctx * gss_get_ctx(struct gss_cl_ctx *ctx) { - atomic_inc(&ctx->count); + refcount_inc(&ctx->count); return ctx; } static inline void gss_put_ctx(struct gss_cl_ctx *ctx) { - if (atomic_dec_and_test(&ctx->count)) + if (refcount_dec_and_test(&ctx->count)) gss_free_ctx(ctx); } @@ -200,7 +200,7 @@ gss_alloc_context(void) ctx->gc_proc = RPC_GSS_PROC_DATA; ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */ spin_lock_init(&ctx->gc_seq_lock); - atomic_set(&ctx->count,1); + refcount_set(&ctx->count,1); } return ctx; } -- 2.34.1