+ mm-fix-potential-memory-leak-in-sys_swapon.patch added to -mm tree

+ mm-fix-potential-memory-leak-in-sys_swapon.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/swapfile.c: fix potential memory leak in sys_swapon
has been added to the -mm tree.  Its filename is
     mm-fix-potential-memory-leak-in-sys_swapon.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-fix-potential-memory-leak-in-sys_swapon.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-potential-memory-leak-in-sys_swapon.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/swapfile.c: fix potential memory leak in sys_swapon

If we failed to drain inode, we would forget to free the swap address
space allocated by init_swap_address_space() above.

Link: https://lkml.kernel.org/r/20200930101803.53884-1-linmiaohe@huawei.com
Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/swapfile.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/swapfile.c~mm-fix-potential-memory-leak-in-sys_swapon
+++ a/mm/swapfile.c
@@ -3338,7 +3338,7 @@ SYSCALL_DEFINE2(swapon, const char __use
 	error = inode_drain_writes(inode);
 	if (error) {
 		inode->i_flags &= ~S_SWAPFILE;
-		goto bad_swap_unlock_inode;
+		goto free_swap_address_space;
 	}
 
 	mutex_lock(&swapon_mutex);
@@ -3363,6 +3363,8 @@ SYSCALL_DEFINE2(swapon, const char __use
 
 	error = 0;
 	goto out;
+free_swap_address_space:
+	exit_swap_address_space(p->type);
 bad_swap_unlock_inode:
 	inode_unlock(inode);
 bad_swap:
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-swap-fix-confusing-comment-in-release_pages.patch
mm-swap_slotsc-remove-always-zero-and-unused-return-value-of-enable_swap_slots_cache.patch
mm-remove-useless-out-label-in-__swap_writepage.patch
mm-fix-incomplete-comment-in-lru_cache_add_inactive_or_unevictable.patch
mm-remove-unnecessary-goto-out-in-_swap_info_get.patch
mm-fix-potential-memory-leak-in-sys_swapon.patch
mm-memcontrol-correct-the-comment-of-mem_cgroup_iter.patch
mm-page_counter-correct-the-obsolete-func-name-in-the-comment-of-page_counter_try_charge.patch
mm-use-helper-function-mapping_allow_writable.patch
mm-mmap-use-helper-function-allow_write_access-in-__remove_shared_vm_struct.patch
mm-mempool-add-else-to-split-mutually-exclusive-case.patch
mm-vmstat-use-helper-macro-abs.patch
mm-fix-some-broken-comments.patch
mm-use-helper-function-put_write_access.patch
percpu_counter-use-helper-macro-abs.patch
mm-migrate-avoid-possible-unnecessary-process-right-check-in-kernel_move_pages.patch