From: Nadia Derbey This patch fixes the missing rcu_read_(un)lock in the ipc code Signed-off-by: Nadia Derbey Signed-off-by: Andrew Morton --- ipc/util.c | 3 ++- ipc/util.h | 4 +++- 2 files changed, 5 insertions(+), 2 deletions(-) diff -puN ipc/util.c~ipc-integrate-ipc_checkid-into-ipc_lock-fix-3 ipc/util.c --- a/ipc/util.c~ipc-integrate-ipc_checkid-into-ipc_lock-fix-3 +++ a/ipc/util.c @@ -295,6 +295,7 @@ int ipc_addid(struct ipc_ids* ids, struc spin_lock_init(&new->lock); new->deleted = 0; + rcu_read_lock(); spin_lock(&new->lock); return id; } @@ -690,7 +691,7 @@ struct kern_ipc_perm *ipc_lock(struct ip rcu_read_unlock(); return ERR_PTR(-EINVAL); } - rcu_read_unlock(); + return out; } diff -puN ipc/util.h~ipc-integrate-ipc_checkid-into-ipc_lock-fix-3 ipc/util.h --- a/ipc/util.h~ipc-integrate-ipc_checkid-into-ipc_lock-fix-3 +++ a/ipc/util.h @@ -135,12 +135,14 @@ static inline int ipc_checkid(struct ipc static inline void ipc_lock_by_ptr(struct kern_ipc_perm *perm) { + rcu_read_lock(); spin_lock(&perm->lock); } static inline void ipc_unlock(struct kern_ipc_perm *perm) { spin_unlock(&perm->lock); + rcu_read_unlock(); } static inline struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, @@ -153,7 +155,7 @@ static inline struct kern_ipc_perm *ipc_ return out; if (ipc_checkid(ids, out, id)) { - spin_unlock(&out->lock); + ipc_unlock(out); return ERR_PTR(-EIDRM); } _