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| author | Miaohe Lin <linmiaohe@huawei.com> | 2022-03-22 22:44:56 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 23:57:07 +0100 |
| commit | 5c2a956c3eea173b2bc89f632507c0eeaebf6c4a (patch) | |
| tree | 8bf905d8e1f63679182309b8679b82bdeec54882 /mm/mlock.c | |
| parent | mm, fault-injection: declare should_fail_alloc_page() (diff) | |
| download | linux-5c2a956c3eea173b2bc89f632507c0eeaebf6c4a.tar.xz linux-5c2a956c3eea173b2bc89f632507c0eeaebf6c4a.zip | |
mm/mlock: fix potential imbalanced rlimit ucounts adjustment
user_shm_lock forgets to set allowed to 0 when get_ucounts fails. So
the later user_shm_unlock might do the extra dec_rlimit_ucounts. Fix
this by resetting allowed to 0.
Link: https://lkml.kernel.org/r/20220310132417.41189-1-linmiaohe@huawei.com
Fixes: d7c9e99aee48 ("Reimplement RLIMIT_MEMLOCK on top of ucounts")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mlock.c')
| -rw-r--r-- | mm/mlock.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index 25934e7db3e1..349e2cda8c50 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -839,6 +839,7 @@ int user_shm_lock(size_t size, struct ucounts *ucounts) } if (!get_ucounts(ucounts)) { dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); + allowed = 0; goto out; } allowed = 1; |