Home
last modified time | relevance | path

Searched hist:ca880420665dbc8beec3693bee9f5eccb89de4a6 (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/fs/
H A Duserfaultfd.cdiff ca880420665dbc8beec3693bee9f5eccb89de4a6 Fri Dec 28 02:34:43 CST 2018 Eric Biggers <ebiggers@google.com> userfaultfd: convert userfaultfd_ctx::refcount to refcount_t

Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs. userfaultfd_ctx::refcount is a
reference counter with the usual semantics, so convert it to refcount_t.

Note: I replaced the BUG() on incrementing a 0 refcount with just
refcount_inc(), since part of the semantics of refcount_t is that that
incrementing a 0 refcount is not allowed; with CONFIG_REFCOUNT_FULL,
refcount_inc() already checks for it and warns.

Link: http://lkml.kernel.org/r/20181115003916.63381-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>