On Fri, Jan 28, 2022 at 5:43 AM Min Hu (Connor) <humin29@huawei.com> wrote:

From: Huisong Li <lihuisong@huawei.com>

The "kni_dev" is the private data of the "net_device" in kni, and allocated
with the "net_device" by calling "alloc_netdev()". The "net_device" is
freed by calling "free_netdev()" when kni release. The freed memory
includes the "kni_dev". So After "kni_dev" should not be accessed after
"net_device" is released.

Fixes: e77fec694936 ("kni: fix possible mbuf leaks and speed up port release")
Cc: stable@dpdk.org

KASAN trace:

[ 85.263717] ==========================================================
[ 85.264418] BUG: KASAN: use-after-free in kni_net_release_fifo_phy+
0x30/0x84 [rte_kni]
[ 85.265139] Read of size 8 at addr ffff000260668d60 by task kni/341
[ 85.265703]
[ 85.265857] CPU: 0 PID: 341 Comm: kni Tainted: G U O
5.15.0-rc4+ #1
[ 85.266525] Hardware name: linux,dummy-virt (DT)
[ 85.266968] Call trace:
[ 85.267220] dump_backtrace+0x0/0x2d0
[ 85.267591] show_stack+0x24/0x30
[ 85.267924] dump_stack_lvl+0x8c/0xb8
[ 85.268294] print_address_description.constprop.0+0x74/0x2b8
[ 85.268855] kasan_report+0x1e4/0x200
[ 85.269224] __asan_load8+0x98/0xd4
[ 85.269577] kni_net_release_fifo_phy+0x30/0x84 [rte_kni]
[ 85.270116] kni_dev_remove.isra.0+0x50/0x64 [rte_kni]
[ 85.270630] kni_ioctl_release+0x254/0x320 [rte_kni]
[ 85.271136] kni_ioctl+0x64/0xb0 [rte_kni]
[ 85.271553] __arm64_sys_ioctl+0xdc/0x120
[ 85.271955] invoke_syscall+0x68/0x1a0
[ 85.272332] el0_svc_common.constprop.0+0x90/0x200
[ 85.272807] do_el0_svc+0x94/0xa4
[ 85.273144] el0_svc+0x78/0x240
[ 85.273463] el0t_64_sync_handler+0x1a8/0x1b0
[ 85.273895] el0t_64_sync+0x1a0/0x1a4
[ 85.274264]
[ 85.274427] Allocated by task 341:
[ 85.274767] kasan_save_stack+0x2c/0x60
[ 85.275157] __kasan_kmalloc+0x90/0xb4
[ 85.275533] __kmalloc_node+0x230/0x594
[ 85.275917] kvmalloc_node+0x8c/0x190
[ 85.276286] alloc_netdev_mqs+0x70/0x6b0
[ 85.276678] kni_ioctl_create+0x224/0xf40 [rte_kni]
[ 85.277166] kni_ioctl+0x9c/0xb0 [rte_kni]
[ 85.277581] __arm64_sys_ioctl+0xdc/0x120
[ 85.277980] invoke_syscall+0x68/0x1a0
[ 85.278357] el0_svc_common.constprop.0+0x90/0x200
[ 85.278830] do_el0_svc+0x94/0xa4
[ 85.279172] el0_svc+0x78/0x240
[ 85.279491] el0t_64_sync_handler+0x1a8/0x1b0
[ 85.279925] el0t_64_sync+0x1a0/0x1a4
[ 85.280292]
[ 85.280454] Freed by task 341:
[ 85.280763] kasan_save_stack+0x2c/0x60
[ 85.281147] kasan_set_track+0x2c/0x40
[ 85.281522] kasan_set_free_info+0x2c/0x50
[ 85.281930] __kasan_slab_free+0xdc/0x140
[ 85.282331] slab_free_freelist_hook+0x90/0x250
[ 85.282782] kfree+0x128/0x580
[ 85.283099] kvfree+0x48/0x60
[ 85.283402] netdev_freemem+0x34/0x44
[ 85.283770] netdev_release+0x50/0x64
[ 85.284138] device_release+0xa0/0x120
[ 85.284516] kobject_put+0xf8/0x160
[ 85.284867] put_device+0x20/0x30
[ 85.285204] free_netdev+0x22c/0x310
[ 85.285562] kni_dev_remove.isra.0+0x48/0x64 [rte_kni]
[ 85.286076] kni_ioctl_release+0x254/0x320 [rte_kni]
[ 85.286573] kni_ioctl+0x64/0xb0 [rte_kni]
[ 85.286992] __arm64_sys_ioctl+0xdc/0x120
[ 85.287392] invoke_syscall+0x68/0x1a0
[ 85.287769] el0_svc_common.constprop.0+0x90/0x200
[ 85.288243] do_el0_svc+0x94/0xa4
[ 85.288579] el0_svc+0x78/0x240
[ 85.288899] el0t_64_sync_handler+0x1a8/0x1b0
[ 85.289332] el0t_64_sync+0x1a0/0x1a4
[ 85.289699]
[ 85.289862] The buggy address belongs to the object at ffff000260668000
[ 85.289862] which belongs to the cache kmalloc-cg-8k of size 8192
[ 85.291079] The buggy address is located 3424 bytes inside of
[ 85.291079] 8192-byte region [ffff000260668000, ffff00026066a000)
[ 85.292213] The buggy address belongs to the page:
[ 85.292684] page:(____ptrval____) refcount:1 mapcount:0 mapping:
0000000000000000 index:0x0 pfn:0x2a0668
[ 85.293585] head:(____ptrval____) order:3 compound_mapcount:0
compound_pincount:0
[ 85.294305] flags: 0xbfff80000010200(slab|head|node=0|zone=2|
lastcpupid=0x7fff)
[ 85.295020] raw: 0bfff80000010200 0000000000000000 dead000000000122
ffff0000c000d680
[ 85.295767] raw: 0000000000000000 0000000080020002 00000001ffffffff
0000000000000000
[ 85.296512] page dumped because: kasan: bad access detected
[ 85.297054]
[ 85.297217] Memory state around the buggy address:
[ 85.297688] ffff000260668c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[ 85.298384] ffff000260668c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[ 85.299088] >ffff000260668d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[ 85.299781] ^
[ 85.300396] ffff000260668d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[ 85.301092] ffff000260668e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb
[ 85.301787] ===========================================================

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
---
kernel/linux/kni/kni_misc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
index f10dcd069d..b3684c4fa6 100644
--- a/kernel/linux/kni/kni_misc.c
+++ b/kernel/linux/kni/kni_misc.c
@@ -184,13 +184,17 @@ kni_dev_remove(struct kni_dev *dev)
if (!dev)
return -ENODEV;

+ /*
+ * The memory of kni device is allocated and released together
+ * with net device. Release mbuf before freeing net device.
+ */
+ kni_net_release_fifo_phy(dev);
+
if (dev->net_dev) {
unregister_netdev(dev->net_dev);
free_netdev(dev->net_dev);
}

- kni_net_release_fifo_phy(dev);
-
return 0;
}

@@ -470,8 +474,8 @@ kni_ioctl_release(struct net *net, uint32_t ioctl_num,
dev->pthread = NULL;
}

- kni_dev_remove(dev);
list_del(&dev->list);
+ kni_dev_remove(dev);
ret = 0;
break;
}
--
2.33.0