From: Nadav Amit namit@vmware.com Subject: mm: respect arch_dup_mmap() return value

d70f2a14b72a4 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc") ignored the return value of arch_dup_mmap(). As a result, on x86, a failure to duplicate the LDT (e.g., due to memory allocation error), would leave the duplicated memory mapping in an inconsistent state.

Fix by regarding the return value, as it was before the change.

Link: http://lkml.kernel.org/r/20180823051229.211856-1-namit@vmware.com Fixes: d70f2a14b72a4 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc") Signed-off-by: Nadav Amit namit@vmware.com Acked-by: Michal Hocko mhocko@suse.com Cc: stable@vger.kernel.org

Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

kernel/fork.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/kernel/fork.c~mm-respect-arch_dup_mmap-return-value +++ a/kernel/fork.c @@ -550,8 +550,7 @@ static __latent_entropy int dup_mmap(str goto out; } /* a new mm has just been created */ - arch_dup_mmap(oldmm, mm); - retval = 0; + retval = arch_dup_mmap(oldmm, mm); out: up_write(&mm->mmap_sem); flush_tlb_mm(oldmm); _