net_sched: fix error recovery at qdisc creation
Dmitry reported uses after free in qdisc code [1]
The problem here is that ops->init() can return an error.
qdisc_create_dflt() then call ops->destroy(),
while qdisc_create() does _not_ call it.
Four qdisc chose to call their own ops->destroy(), assuming their caller
would not.
This patch makes sure qdisc_create() calls ops->destroy()
and fixes the four qdisc to avoid double free.
[1]
BUG: KASAN: use-after-free in mq_destroy+0x242/0x290 net/sched/sch_mq.c:33 at addr ffff8801d415d440
Read of size 8 by task syz-executor2/5030
CPU: 0 PID: 5030 Comm: syz-executor2 Not tainted 4.3.5-smp-DEV #119
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
0000000000000046 ffff8801b435b870 ffffffff81bbbed4 ffff8801db000400
ffff8801d415d440 ffff8801d415dc40 ffff8801c4988510 ffff8801b435b898
ffffffff816682b1 ffff8801b435b928 ffff8801d415d440 ffff8801c49880c0
Call Trace:
[<ffffffff81bbbed4>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffffff81bbbed4>] dump_stack+0x6c/0x98 lib/dump_stack.c:51
[<ffffffff816682b1>] kasan_object_err+0x21/0x70 mm/kasan/report.c:158
[<ffffffff81668524>] print_address_description mm/kasan/report.c:196 [inline]
[<ffffffff81668524>] kasan_report_error+0x1b4/0x4b0 mm/kasan/report.c:285
[<ffffffff81668953>] kasan_report mm/kasan/report.c:305 [inline]
[<ffffffff81668953>] __asan_report_load8_noabort+0x43/0x50 mm/kasan/report.c:326
[<ffffffff82527b02>] mq_destroy+0x242/0x290 net/sched/sch_mq.c:33
[<ffffffff82524bdd>] qdisc_destroy+0x12d/0x290 net/sched/sch_generic.c:953
[<ffffffff82524e30>] qdisc_create_dflt+0xf0/0x120 net/sched/sch_generic.c:848
[<ffffffff8252550d>] attach_default_qdiscs net/sched/sch_generic.c:1029 [inline]
[<ffffffff8252550d>] dev_activate+0x6ad/0x880 net/sched/sch_generic.c:1064
[<ffffffff824b1db1>] __dev_open+0x221/0x320 net/core/dev.c:1403
[<ffffffff824b24ce>] __dev_change_flags+0x15e/0x3e0 net/core/dev.c:6858
[<ffffffff824b27de>] dev_change_flags+0x8e/0x140 net/core/dev.c:6926
[<ffffffff824f5bf6>] dev_ifsioc+0x446/0x890 net/core/dev_ioctl.c:260
[<ffffffff824f61fa>] dev_ioctl+0x1ba/0xb80 net/core/dev_ioctl.c:546
[<ffffffff82430509>] sock_do_ioctl+0x99/0xb0 net/socket.c:879
[<ffffffff82430d30>] sock_ioctl+0x2a0/0x390 net/socket.c:958
[<ffffffff816f3b68>] vfs_ioctl fs/ioctl.c:44 [inline]
[<ffffffff816f3b68>] do_vfs_ioctl+0x8a8/0xe50 fs/ioctl.c:611
[<ffffffff816f41a4>] SYSC_ioctl fs/ioctl.c:626 [inline]
[<ffffffff816f41a4>] SyS_ioctl+0x94/0xc0 fs/ioctl.c:617
[<ffffffff8123e357>] entry_SYSCALL_64_fastpath+0x12/0x17
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c
index e3d0458..2fae8b5 100644
--- a/net/sched/sch_hhf.c
+++ b/net/sched/sch_hhf.c
@@ -627,7 +627,9 @@
q->hhf_arrays[i] = hhf_zalloc(HHF_ARRAYS_LEN *
sizeof(u32));
if (!q->hhf_arrays[i]) {
- hhf_destroy(sch);
+ /* Note: hhf_destroy() will be called
+ * by our caller.
+ */
return -ENOMEM;
}
}
@@ -638,7 +640,9 @@
q->hhf_valid_bits[i] = hhf_zalloc(HHF_ARRAYS_LEN /
BITS_PER_BYTE);
if (!q->hhf_valid_bits[i]) {
- hhf_destroy(sch);
+ /* Note: hhf_destroy() will be called
+ * by our caller.
+ */
return -ENOMEM;
}
}