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author | Andrea Arcangeli <aarcange@redhat.com> | 2019-06-28 22:07:14 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-06-29 11:43:45 +0300 |
commit | 1bf4580e00a248a2c86269125390eb3648e1877c (patch) | |
tree | 63f8510d48380fcf5d8133c2270b45501106769d /mm | |
parent | 8708e13c6a0600625eea3aebd027c0715a5d2bb2 (diff) | |
download | linux-1bf4580e00a248a2c86269125390eb3648e1877c.tar.xz |
fork,memcg: alloc_thread_stack_node needs to set tsk->stack
Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on
memcg charge fail") corrected two instances, but there was a third
instance of this bug.
Without setting tsk->stack, if memcg_charge_kernel_stack fails, it'll
execute free_thread_stack() on a dangling pointer.
Enterprise kernels are compiled with VMAP_STACK=y so this isn't
critical, but custom VMAP_STACK=n builds should have some performance
advantage, with the drawback of risking to fail fork because compaction
didn't succeed. So as long as VMAP_STACK=n is a supported option it's
worth fixing it upstream.
Link: http://lkml.kernel.org/r/20190619011450.28048-1-aarcange@redhat.com
Fixes: 9b6f7e163cd0 ("mm: rework memcg kernel stack accounting")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions