4.18-stable review patch. If anyone has any objections, please let me know.
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From: Nadav Amit namit@vmware.com
commit 1ed0cc5a01a4d868d9907ce96468c4b4c6709556 upstream.
Commit d70f2a14b72a ("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 using 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: Greg Kroah-Hartman gregkh@linuxfoundation.org
Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org
--- kernel/fork.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/kernel/fork.c +++ b/kernel/fork.c @@ -549,8 +549,7 @@ 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);