* [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early
@ 2021-12-01 3:02 Dust Li
2021-12-01 6:34 ` Tony Lu
2021-12-02 12:20 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Dust Li @ 2021-12-01 3:02 UTC (permalink / raw)
To: Karsten Graul, David S . Miller, Jakub Kicinski, Ursula Braun
Cc: Tony Lu, Wen Gu, linux-s390, netdev
smc_lgr_cleanup_early() meant to delete the link
group from the link group list, but it deleted
the list head by mistake.
This may cause memory corruption since we didn't
remove the real link group from the list and later
memseted the link group structure.
We got a list corruption panic when testing:
[ 231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000
[ 231.278222] ------------[ cut here ]------------
[ 231.278726] kernel BUG at lib/list_debug.c:53!
[ 231.279326] invalid opcode: 0000 [#1] SMP NOPTI
[ 231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435
[ 231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
[ 231.281248] Workqueue: events smc_link_down_work
[ 231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90
[ 231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c
60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f>
0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc
[ 231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292
[ 231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000
[ 231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040
[ 231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001
[ 231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001
[ 231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003
[ 231.288337] FS: 0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
[ 231.289160] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0
[ 231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 231.291940] Call Trace:
[ 231.292211] smc_lgr_terminate_sched+0x53/0xa0
[ 231.292677] smc_switch_conns+0x75/0x6b0
[ 231.293085] ? update_load_avg+0x1a6/0x590
[ 231.293517] ? ttwu_do_wakeup+0x17/0x150
[ 231.293907] ? update_load_avg+0x1a6/0x590
[ 231.294317] ? newidle_balance+0xca/0x3d0
[ 231.294716] smcr_link_down+0x50/0x1a0
[ 231.295090] ? __wake_up_common_lock+0x77/0x90
[ 231.295534] smc_link_down_work+0x46/0x60
[ 231.295933] process_one_work+0x18b/0x350
Fixes: a0a62ee15a829 ("net/smc: separate locks for SMCD and SMCR link group lists")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
---
v2: Remove unused lgr_list
v2->v3: Fix uninitialized lgr_lock, thanks Jakub Kicinski !
---
net/smc/smc_core.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index bb52c8b5f148..387d28b2f8dd 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -625,18 +625,17 @@ int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
void smc_lgr_cleanup_early(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
- struct list_head *lgr_list;
spinlock_t *lgr_lock;
if (!lgr)
return;
smc_conn_free(conn);
- lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
+ smc_lgr_list_head(lgr, &lgr_lock);
spin_lock_bh(lgr_lock);
/* do not use this link group for new connections */
- if (!list_empty(lgr_list))
- list_del_init(lgr_list);
+ if (!list_empty(&lgr->list))
+ list_del_init(&lgr->list);
spin_unlock_bh(lgr_lock);
__smc_lgr_terminate(lgr, true);
}
--
2.19.1.3.ge56e4f7
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early
2021-12-01 3:02 [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early Dust Li
@ 2021-12-01 6:34 ` Tony Lu
2021-12-02 12:20 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Tony Lu @ 2021-12-01 6:34 UTC (permalink / raw)
To: Dust Li
Cc: Karsten Graul, David S . Miller, Jakub Kicinski, Ursula Braun,
Wen Gu, linux-s390, netdev
On Wed, Dec 01, 2021 at 11:02:30AM +0800, Dust Li wrote:
> smc_lgr_cleanup_early() meant to delete the link
> group from the link group list, but it deleted
> the list head by mistake.
>
> This may cause memory corruption since we didn't
> remove the real link group from the list and later
> memseted the link group structure.
> We got a list corruption panic when testing:
>
> [ 231.277259] list_del corruption. prev->next should be ffff8881398a8000, but was 0000000000000000
> [ 231.278222] ------------[ cut here ]------------
> [ 231.278726] kernel BUG at lib/list_debug.c:53!
> [ 231.279326] invalid opcode: 0000 [#1] SMP NOPTI
> [ 231.279803] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.10.46+ #435
> [ 231.280466] Hardware name: Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
> [ 231.281248] Workqueue: events smc_link_down_work
> [ 231.281732] RIP: 0010:__list_del_entry_valid+0x70/0x90
> [ 231.282258] Code: 4c 60 82 e8 7d cc 6a 00 0f 0b 48 89 fe 48 c7 c7 88 4c
> 60 82 e8 6c cc 6a 00 0f 0b 48 89 fe 48 c7 c7 c0 4c 60 82 e8 5b cc 6a 00 <0f>
> 0b 48 89 fe 48 c7 c7 00 4d 60 82 e8 4a cc 6a 00 0f 0b cc cc cc
> [ 231.284146] RSP: 0018:ffffc90000033d58 EFLAGS: 00010292
> [ 231.284685] RAX: 0000000000000054 RBX: ffff8881398a8000 RCX: 0000000000000000
> [ 231.285415] RDX: 0000000000000001 RSI: ffff88813bc18040 RDI: ffff88813bc18040
> [ 231.286141] RBP: ffffffff8305ad40 R08: 0000000000000003 R09: 0000000000000001
> [ 231.286873] R10: ffffffff82803da0 R11: ffffc90000033b90 R12: 0000000000000001
> [ 231.287606] R13: 0000000000000000 R14: ffff8881398a8000 R15: 0000000000000003
> [ 231.288337] FS: 0000000000000000(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
> [ 231.289160] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 231.289754] CR2: 0000000000e72058 CR3: 000000010fa96006 CR4: 00000000003706f0
> [ 231.290485] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 231.291211] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 231.291940] Call Trace:
> [ 231.292211] smc_lgr_terminate_sched+0x53/0xa0
> [ 231.292677] smc_switch_conns+0x75/0x6b0
> [ 231.293085] ? update_load_avg+0x1a6/0x590
> [ 231.293517] ? ttwu_do_wakeup+0x17/0x150
> [ 231.293907] ? update_load_avg+0x1a6/0x590
> [ 231.294317] ? newidle_balance+0xca/0x3d0
> [ 231.294716] smcr_link_down+0x50/0x1a0
> [ 231.295090] ? __wake_up_common_lock+0x77/0x90
> [ 231.295534] smc_link_down_work+0x46/0x60
> [ 231.295933] process_one_work+0x18b/0x350
>
> Fixes: a0a62ee15a829 ("net/smc: separate locks for SMCD and SMCR link group lists")
> Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
> Acked-by: Karsten Graul <kgraul@linux.ibm.com>
This patch looks good to me, thank you.
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
> ---
> v2: Remove unused lgr_list
> v2->v3: Fix uninitialized lgr_lock, thanks Jakub Kicinski !
> ---
> net/smc/smc_core.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
> index bb52c8b5f148..387d28b2f8dd 100644
> --- a/net/smc/smc_core.c
> +++ b/net/smc/smc_core.c
> @@ -625,18 +625,17 @@ int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
> void smc_lgr_cleanup_early(struct smc_connection *conn)
> {
> struct smc_link_group *lgr = conn->lgr;
> - struct list_head *lgr_list;
> spinlock_t *lgr_lock;
>
> if (!lgr)
> return;
>
> smc_conn_free(conn);
> - lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
> + smc_lgr_list_head(lgr, &lgr_lock);
> spin_lock_bh(lgr_lock);
> /* do not use this link group for new connections */
> - if (!list_empty(lgr_list))
> - list_del_init(lgr_list);
> + if (!list_empty(&lgr->list))
> + list_del_init(&lgr->list);
> spin_unlock_bh(lgr_lock);
> __smc_lgr_terminate(lgr, true);
> }
> --
> 2.19.1.3.ge56e4f7
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early
2021-12-01 3:02 [PATCH net v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early Dust Li
2021-12-01 6:34 ` Tony Lu
@ 2021-12-02 12:20 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-12-02 12:20 UTC (permalink / raw)
To: Dust Li; +Cc: kgraul, davem, kuba, ubraun, tonylu, guwen, linux-s390, netdev
Hello:
This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:
On Wed, 1 Dec 2021 11:02:30 +0800 you wrote:
> smc_lgr_cleanup_early() meant to delete the link
> group from the link group list, but it deleted
> the list head by mistake.
>
> This may cause memory corruption since we didn't
> remove the real link group from the list and later
> memseted the link group structure.
> We got a list corruption panic when testing:
>
> [...]
Here is the summary with links:
- [net,v3] net/smc: fix wrong list_del in smc_lgr_cleanup_early
https://git.kernel.org/netdev/net/c/789b6cc2a5f9
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-12-02 12:20 ` patchwork-bot+netdevbpf
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