tree 889339bdce44c612c179d28ab9209978e85eef48
parent b20078fd69a3da08d85c79b95101cf25c4afcc97
author Linus Torvalds <torvalds@linux-foundation.org> 1635104913 -1000
committer Linus Torvalds <torvalds@linux-foundation.org> 1635104913 -1000

Revert "mm/secretmem: use refcount_t instead of atomic_t"

This reverts commit 110860541f443f950c1274f217a1a3e298670a33.

Converting the "secretmem_users" counter to a refcount is incorrect,
because a refcount is special in zero and can't just be incremented (but
a count of users is not, and "no users" is actually perfectly valid and
not a sign of a free'd resource).

Reported-by: syzbot+75639e6a0331cd61d3e2@syzkaller.appspotmail.com
Cc: Jordy Zomer <jordy@pwning.systems>
Cc: Kees Cook <keescook@chromium.org>,
Cc: Jordy Zomer <jordy@jordyzomer.github.io>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>