Commits
Dmitry Eremin committed 9b046013e58
staging: lustre: separate a connection destroy from free struct kib_conn
The logic of the original commit 4d99b2581eff ("staging: lustre: avoid
intensive reconnecting for ko2iblnd") was assumed conditional free of
struct kib_conn if the second argument free_conn in function
kiblnd_destroy_conn(struct kib_conn *conn, bool free_conn) is true.
But this hunk of code was dropped from original commit. As result the logic
works wrong and current code use struct kib_conn after free.
> drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
> 3317 kiblnd_destroy_conn(conn, !peer);
> ^^^^ Freed always (but should be conditionally)
> 3318
> 3319 spin_lock_irqsave(lock, flags);
> 3320 if (!peer)
> 3321 continue;
> 3322
> 3323 conn->ibc_peer = peer;
> ^^^^^^^^^^^^^^ Use after free
> 3324 if (peer->ibp_reconnected < KIB_RECONN_HIGH_RACE)
> 3325 list_add_tail(&conn->ibc_list,
> ^^^^^^^^^^^^^^ Use after free
> 3326 &kiblnd_data.kib_reconn_list);
> 3327 else
> 3328 list_add_tail(&conn->ibc_list,
> ^^^^^^^^^^^^^^ Use after free
> 3329 &kiblnd_data.kib_reconn_wait);
To avoid confusion this fix moved the freeing a struct kib_conn outside of
the function kiblnd_destroy_conn() and free as it was intended in original
commit.
Cc: <stable@vger.kernel.org> # v4.6
Fixes: 4d99b2581eff ("staging: lustre: avoid intensive reconnecting for ko2iblnd")
Signed-off-by: Dmitry Eremin <Dmitry.Eremin@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>