diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-02-10 21:31:49 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-12 05:38:58 +0300 |
| commit | 87b60cfacf9f17cf71933c6e33b66e68160af71d (patch) | |
| tree | 2515afd95734510a26052154f094c3064063777d /net/sched/sch_api.c | |
| parent | 1bf960502e4c94425c3a3a985200834fb59839c6 (diff) | |
| download | linux-87b60cfacf9f17cf71933c6e33b66e68160af71d.tar.xz | |
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>
Diffstat (limited to 'net/sched/sch_api.c')
| -rw-r--r-- | net/sched/sch_api.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index adeabaec0d0b..a13c15e8f087 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1019,6 +1019,8 @@ static struct Qdisc *qdisc_create(struct net_device *dev, return sch; } + /* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */ + ops->destroy(sch); err_out3: dev_put(dev); kfree((char *) sch - sch->padded); |