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| author | Hoang Le <hoang.h.le@dektech.com.au> | 2021-01-08 10:13:37 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-23 17:38:19 +0300 |
| commit | 310014f572a59b311c175321265a08c9adfced0c (patch) | |
| tree | 678b7c89a2d721b14d370a1be2580fa23501beab | |
| parent | 4a4ba4a0bd096a2e90bd0d0d1e6b238547906738 (diff) | |
| download | linux-310014f572a59b311c175321265a08c9adfced0c.tar.xz | |
tipc: fix NULL deref in tipc_link_xmit()
[ Upstream commit b77413446408fdd256599daf00d5be72b5f3e7c6 ]
The buffer list can have zero skb as following path:
tipc_named_node_up()->tipc_node_xmit()->tipc_link_xmit(), so
we need to check the list before casting an &sk_buff.
Fault report:
[] tipc: Bulk publication failure
[] general protection fault, probably for non-canonical [#1] PREEMPT [...]
[] KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
[] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 5.10.0-rc4+ #2
[] Hardware name: Bochs ..., BIOS Bochs 01/01/2011
[] RIP: 0010:tipc_link_xmit+0xc1/0x2180
[] Code: 24 b8 00 00 00 00 4d 39 ec 4c 0f 44 e8 e8 d7 0a 10 f9 48 [...]
[] RSP: 0018:ffffc90000006ea0 EFLAGS: 00010202
[] RAX: dffffc0000000000 RBX: ffff8880224da000 RCX: 1ffff11003d3cc0d
[] RDX: 0000000000000019 RSI: ffffffff886007b9 RDI: 00000000000000c8
[] RBP: ffffc90000007018 R08: 0000000000000001 R09: fffff52000000ded
[] R10: 0000000000000003 R11: fffff52000000dec R12: ffffc90000007148
[] R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000007018
[] FS: 0000000000000000(0000) GS:ffff888037400000(0000) knlGS:000[...]
[] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[] CR2: 00007fffd2db5000 CR3: 000000002b08f000 CR4: 00000000000006f0
Fixes: af9b028e270fd ("tipc: make media xmit call outside node spinlock context")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Link: https://lore.kernel.org/r/20210108071337.3598-1-hoang.h.le@dektech.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/tipc/link.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c index c7406c1fdc14..06327f78f203 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -877,9 +877,8 @@ void tipc_link_reset(struct tipc_link *l) int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, struct sk_buff_head *xmitq) { - struct tipc_msg *hdr = buf_msg(skb_peek(list)); unsigned int maxwin = l->window; - unsigned int i, imp = msg_importance(hdr); + unsigned int i; unsigned int mtu = l->mtu; u16 ack = l->rcv_nxt - 1; u16 seqno = l->snd_nxt; @@ -888,7 +887,13 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, struct sk_buff_head *backlogq = &l->backlogq; struct sk_buff *skb, *_skb, *bskb; int pkt_cnt = skb_queue_len(list); + struct tipc_msg *hdr; + int imp; + + if (pkt_cnt <= 0) + return 0; + imp = msg_importance(hdr); /* Match msg importance against this and all higher backlog limits: */ if (!skb_queue_empty(backlogq)) { for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) { @@ -896,6 +901,8 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, return link_schedule_user(l, list); } } + + hdr = buf_msg(skb_peek(list)); if (unlikely(msg_size(hdr) > mtu)) { skb_queue_purge(list); return -EMSGSIZE; |