Commit 1ed0cc5a authored Sep 04, 2018 by Nadav Amit Committed by Linus Torvalds Sep 04, 2018

mm: respect arch_dup_mmap() return value

Commit d70f2a14 ("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: d70f2a14 ("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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 79cc8105

kernel/fork.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -550,8 +550,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
		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);

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