From: Eric Dumazet edumazet@google.com
[ Upstream commit 0ff4628f4c6c1ab87eef9f16b25355cadc426d64 ]
syzbot reported a bug in ieee802154_tx() [1]
A similar issue in ieee802154_xmit_worker() is also fixed in this patch.
[1] BUG: KASAN: use-after-free in ieee802154_tx+0x3d2/0x480 net/mac802154/tx.c:88 Read of size 4 at addr ffff8880251a8c70 by task syz-executor.3/928
CPU: 0 PID: 928 Comm: syz-executor.3 Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 ieee802154_tx+0x3d2/0x480 net/mac802154/tx.c:88 ieee802154_subif_start_xmit+0xbe/0xe4 net/mac802154/tx.c:130 __netdev_start_xmit include/linux/netdevice.h:4634 [inline] netdev_start_xmit include/linux/netdevice.h:4648 [inline] dev_direct_xmit+0x4e9/0x6e0 net/core/dev.c:4203 packet_snd net/packet/af_packet.c:2989 [inline] packet_sendmsg+0x2413/0x5290 net/packet/af_packet.c:3014 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc98e749c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002ccc0 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000020007780 RDI: 000000000000000b RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007fff690c720f R14: 00007fc98e74a9c0 R15: 000000000118cfec
Allocated by task 928: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc_node mm/slab.c:3254 [inline] kmem_cache_alloc_node+0x136/0x3e0 mm/slab.c:3574 __alloc_skb+0x71/0x550 net/core/skbuff.c:198 alloc_skb include/linux/skbuff.h:1094 [inline] alloc_skb_with_frags+0x92/0x570 net/core/skbuff.c:5771 sock_alloc_send_pskb+0x72a/0x880 net/core/sock.c:2348 packet_alloc_skb net/packet/af_packet.c:2837 [inline] packet_snd net/packet/af_packet.c:2932 [inline] packet_sendmsg+0x19fb/0x5290 net/packet/af_packet.c:3014 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 928: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x74/0x1e0 mm/slab.c:3693 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:622 __kfree_skb net/core/skbuff.c:679 [inline] consume_skb net/core/skbuff.c:838 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:832 __dev_kfree_skb_any+0x9c/0xc0 net/core/dev.c:3107 fakelb_hw_xmit+0x20e/0x2a0 drivers/net/ieee802154/fakelb.c:81 drv_xmit_async net/mac802154/driver-ops.h:16 [inline] ieee802154_tx+0x282/0x480 net/mac802154/tx.c:81 ieee802154_subif_start_xmit+0xbe/0xe4 net/mac802154/tx.c:130 __netdev_start_xmit include/linux/netdevice.h:4634 [inline] netdev_start_xmit include/linux/netdevice.h:4648 [inline] dev_direct_xmit+0x4e9/0x6e0 net/core/dev.c:4203 packet_snd net/packet/af_packet.c:2989 [inline] packet_sendmsg+0x2413/0x5290 net/packet/af_packet.c:3014 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8880251a8c00 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 112 bytes inside of 224-byte region [ffff8880251a8c00, ffff8880251a8ce0) The buggy address belongs to the page: page:0000000062b6a4f1 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x251a8 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0000435c88 ffffea00028b6c08 ffff8880a9055d00 raw: 0000000000000000 ffff8880251a80c0 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8880251a8b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880251a8b80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880251a8c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff8880251a8c80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880251a8d00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
Fixes: 409c3b0c5f03 ("mac802154: tx: move stats tx increment") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Cc: Alexander Aring alex.aring@gmail.com Cc: Stefan Schmidt stefan@datenfreihafen.org Cc: linux-wpan@vger.kernel.org Link: https://lore.kernel.org/r/20200908104025.4009085-1-edumazet@google.com Signed-off-by: Stefan Schmidt stefan@datenfreihafen.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac802154/tx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c index ab52811523e99..c829e4a753256 100644 --- a/net/mac802154/tx.c +++ b/net/mac802154/tx.c @@ -34,11 +34,11 @@ void ieee802154_xmit_worker(struct work_struct *work) if (res) goto err_tx;
- ieee802154_xmit_complete(&local->hw, skb, false); - dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len;
+ ieee802154_xmit_complete(&local->hw, skb, false); + return;
err_tx: @@ -78,6 +78,8 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
/* async is priority, otherwise sync is fallback */ if (local->ops->xmit_async) { + unsigned int len = skb->len; + ret = drv_xmit_async(local, skb); if (ret) { ieee802154_wake_queue(&local->hw); @@ -85,7 +87,7 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb) }
dev->stats.tx_packets++; - dev->stats.tx_bytes += skb->len; + dev->stats.tx_bytes += len; } else { local->tx_skb = skb; queue_work(local->workqueue, &local->tx_work);