diff options
| author | Liam R. Howlett <Liam.Howlett@oracle.com> | 2023-03-08 17:03:10 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-30 12:51:41 +0200 |
| commit | b4f664ffd8f78c05a1fd542a28bc5a11e994c014 (patch) | |
| tree | 177ad5252104a822c310845ab7d863c052d99860 /lib/net_utils.c | |
| parent | e62c1839e71c36fe3a24951eef8d179be726fd4b (diff) | |
mm/ksm: fix race with VMA iteration and mm_struct teardown
commit 6db504ce55bdbc575723938fc480713c9183f6a2 upstream.
exit_mmap() will tear down the VMAs and maple tree with the mmap_lock held
in write mode. Ensure that the maple tree is still valid by checking
ksm_test_exit() after taking the mmap_lock in read mode, but before the
for_each_vma() iterator dereferences a destroyed maple tree.
Since the maple tree is destroyed, the flags telling lockdep to check an
external lock has been cleared. Skip the for_each_vma() iterator to avoid
dereferencing a maple tree without the external lock flag, which would
create a lockdep warning.
Link: https://lkml.kernel.org/r/20230308220310.3119196-1-Liam.Howlett@oracle.com
Fixes: a5f18ba07276 ("mm/ksm: use vma iterators instead of vma linked list")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Link: https://lore.kernel.org/lkml/ZAdUUhSbaa6fHS36@xpf.sh.intel.com/
Reported-by: syzbot+2ee18845e89ae76342c5@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=64a3e95957cd3deab99df7cd7b5a9475af92c93e
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <heng.su@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/net_utils.c')
0 files changed, 0 insertions, 0 deletions