This is a note to let you know that I've just added the patch titled
net: sched: fix panic in rate estimators
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-sched-fix-panic-in-rate-estimators.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Feb 12 09:25:54 HKT 2015
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Thu, 29 Jan 2015 17:30:12 -0800
Subject: net: sched: fix panic in rate estimators
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 0d32ef8cef9aa8f375e128f78b77caceaa7e8da0 ]
Doing the following commands on a non idle network device
panics the box instantly, because cpu_bstats gets overwritten
by stats.
tc qdisc add dev eth0 root <your_favorite_qdisc>
... some traffic (one packet is enough) ...
tc qdisc replace dev eth0 root est 1sec 4sec <your_favorite_qdisc>
[ 325.355596] BUG: unable to handle kernel paging request at ffff8841dc5a074c
[ 325.362609] IP: [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90
[ 325.369158] PGD 1fa7067 PUD 0
[ 325.372254] Oops: 0000 [#1] SMP
[ 325.375514] Modules linked in: ...
[ 325.398346] CPU: 13 PID: 14313 Comm: tc Not tainted 3.19.0-smp-DEV #1163
[ 325.412042] task: ffff8800793ab5d0 ti: ffff881ff2fa4000 task.ti: ffff881ff2fa4000
[ 325.419518] RIP: 0010:[<ffffffff81541c9e>] [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90
[ 325.428506] RSP: 0018:ffff881ff2fa7928 EFLAGS: 00010286
[ 325.433824] RAX: 000000000000000c RBX: ffff881ff2fa796c RCX: 000000000000000c
[ 325.440988] RDX: ffff8841dc5a0744 RSI: 0000000000000060 RDI: 0000000000000060
[ 325.448120] RBP: ffff881ff2fa7948 R08: ffffffff81cd4f80 R09: 0000000000000000
[ 325.455268] R10: ffff883ff223e400 R11: 0000000000000000 R12: 000000015cba0744
[ 325.462405] R13: ffffffff81cd4f80 R14: ffff883ff223e460 R15: ffff883feea0722c
[ 325.469536] FS: 00007f2ee30fa700(0000) GS:ffff88407fa20000(0000) knlGS:0000000000000000
[ 325.477630] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 325.483380] CR2: ffff8841dc5a074c CR3: 0000003feeae9000 CR4: 00000000001407e0
[ 325.490510] Stack:
[ 325.492524] ffff883feea0722c ffff883fef719dc0 ffff883feea0722c ffff883ff223e4a0
[ 325.499990] ffff881ff2fa79a8 ffffffff815424ee ffff883ff223e49c 000000015cba0744
[ 325.507460] 00000000f2fa7978 0000000000000000 ffff881ff2fa79a8 ffff883ff223e4a0
[ 325.514956] Call Trace:
[ 325.517412] [<ffffffff815424ee>] gen_new_estimator+0x8e/0x230
[ 325.523250] [<ffffffff815427aa>] gen_replace_estimator+0x4a/0x60
[ 325.529349] [<ffffffff815718ab>] tc_modify_qdisc+0x52b/0x590
[ 325.535117] [<ffffffff8155edd0>] rtnetlink_rcv_msg+0xa0/0x240
[ 325.540963] [<ffffffff8155ed30>] ? __rtnl_unlock+0x20/0x20
[ 325.546532] [<ffffffff8157f811>] netlink_rcv_skb+0xb1/0xc0
[ 325.552145] [<ffffffff8155b355>] rtnetlink_rcv+0x25/0x40
[ 325.557558] [<ffffffff8157f0d8>] netlink_unicast+0x168/0x220
[ 325.563317] [<ffffffff8157f47c>] netlink_sendmsg+0x2ec/0x3e0
Lets play safe and not use an union : percpu 'pointers' are mostly read
anyway, and we have typically few qdiscs per host.
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe")
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/sch_generic.h | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -79,6 +79,9 @@ struct Qdisc {
struct netdev_queue *dev_queue;
struct gnet_stats_rate_est64 rate_est;
+ struct gnet_stats_basic_cpu __percpu *cpu_bstats;
+ struct gnet_stats_queue __percpu *cpu_qstats;
+
struct Qdisc *next_sched;
struct sk_buff *gso_skb;
/*
@@ -86,15 +89,9 @@ struct Qdisc {
*/
unsigned long state;
struct sk_buff_head q;
- union {
- struct gnet_stats_basic_packed bstats;
- struct gnet_stats_basic_cpu __percpu *cpu_bstats;
- } __packed;
+ struct gnet_stats_basic_packed bstats;
unsigned int __state;
- union {
- struct gnet_stats_queue qstats;
- struct gnet_stats_queue __percpu *cpu_qstats;
- } __packed;
+ struct gnet_stats_queue qstats;
struct rcu_head rcu_head;
int padded;
atomic_t refcnt;
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-3.18/tcp-ipv4-initialize-unicast_sock-sk_pacing_rate.patch
queue-3.18/net-sched-fix-panic-in-rate-estimators.patch
queue-3.18/ip-zero-sockaddr-returned-on-error-queue.patch
queue-3.18/ping-fix-race-in-free-in-receive-path.patch
queue-3.18/net-rps-fix-cpu-unplug.patch
queue-3.18/netxen-fix-netxen_nic_poll-logic.patch
queue-3.18/ipv4-tcp-get-rid-of-ugly-unicast_sock.patch
queue-3.18/bnx2x-fix-napi-poll-return-value-for-repoll.patch
--
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