Re: [Qestion] Lots of memory leaks when mounting and unmounting nfs client to server continuously.

[Benjamin Coddington]

Hi zhong jiang,

Try asking in linux-nfs.. but I'll also note that 3.10-stable may be 
missing a number of fixes to leaks in the NFS GSS code.

I can see a more than a few fixes to memory leaks with:
git log --grep=leak --oneline net/sunrpc/auth_gss/

Ben

On 30 Oct 2018, at 8:45, zhong jiang wrote:

> Hi,   Herbert
>
> Recently,  I  hit  a memory leak issue when  mounting and unmounting 
> nfs with  the way of  krb5.
> The issue happens to the linux-3.10-stable.
>
> I find that slab-1024 and slab-512 will take up most of the memory.  
> And it can not be freed.
> Meanwhile, it result in rpcsec_gss_krb5 can be unregistered as well.
>
> nfs-sve1:/home # cat /proc/modules | grep krb5
> rpcsec_gss_krb5 31477 239730 - Live 0xffffffffa0334000
> auth_rpcgss 59314 3 rpcsec_gss_krb5,nfsd, Live 0xffffffffa0123000
> sunrpc 300546 25 rpcsec_gss_krb5,nfsd,auth_rpcgss,nfs_acl,lockd, Live 
> 0xffffffffa013b000
>
> I open the slab-1024 trace by enabling 
> /sys/kernel/slab/:t-0001024/trace and get the following
>
> [123420.989831] Call Trace:
> [123420.989834]  [<ffffffff81642d2a>] dump_stack+0x19/0x1b
> [123420.989837]  [<ffffffff8163f25e>] 
> alloc_debug_processing+0xc5/0x118
> [123420.989839]  [<ffffffff8163fd4d>] __slab_alloc+0x400/0x48f
> [123420.989841]  [<ffffffff812b1795>] ? __crypto_alloc_tfm+0x45/0x170
> [123420.989845]  [<ffffffff812b2307>] ? setkey+0x57/0x110
> [123420.989847]  [<ffffffff8118b5fd>] ? kzfree+0x2d/0x30
> [123420.989850]  [<ffffffff811c6e88>] __kmalloc+0x1c8/0x230
> [123420.989852]  [<ffffffff812b1795>] __crypto_alloc_tfm+0x45/0x170
> [123420.989854]  [<ffffffff812b2e45>] crypto_spawn_tfm+0x45/0x80
> [123420.989857]  [<ffffffff811c6eb3>] ? __kmalloc+0x1f3/0x230
> [123420.989859]  [<ffffffff812c15c7>] crypto_cbc_init_tfm+0x27/0x40
> [123420.989864]  [<ffffffff812b1851>] __crypto_alloc_tfm+0x101/0x170
> [123420.989866]  [<ffffffff812b1ffc>] crypto_alloc_base+0x4c/0xb0
> [123420.989869]  [<ffffffffa033411b>] 
> context_v2_alloc_cipher.isra.2+0x2b/0xc0 [rpcsec_gss_krb5]
> [123420.989871]  [<ffffffffa0334da8>] 
> gss_import_sec_context_kerberos+0xbf8/0xf00 [rpcsec_gss_krb5]
> [123420.989875]  [<ffffffffa0126d5d>] gss_import_sec_context+0x7d/0xb0 
> [auth_rpcgss]
> [123420.989878]  [<ffffffffa012b35e>] gss_proxy_save_rsc+0x137/0x1b0 
> [auth_rpcgss]
> [123420.989884]  [<ffffffffa012b51e>] 
> svcauth_gss_proxy_init+0x147/0x1e4 [auth_rpcgss]
> [123420.989886]  [<ffffffff810c2ad6>] ? dequeue_entity+0x106/0x520
> [123420.989890]  [<ffffffffa0128e2a>] svcauth_gss_accept+0x3da/0xb70 
> [auth_rpcgss]
> [123420.989892]  [<ffffffff810b6c25>] ? check_preempt_curr+0x85/0xa0
> [123420.989894]  [<ffffffff810b6c59>] ? ttwu_do_wakeup+0x19/0xd0
> [123420.989897]  [<ffffffff810b6ded>] ? 
> ttwu_do_activate.constprop.86+0x5d/0x70
> [123420.989900]  [<ffffffff810b9422>] ? try_to_wake_up+0x162/0x330
> [123420.989908]  [<ffffffffa014f490>] svc_authenticate+0xc0/0xe0 
> [sunrpc]
> [123420.989914]  [<ffffffffa014c04a>] svc_process_common+0x21a/0x6f0 
> [sunrpc]
> [123420.989921]  [<ffffffffa014c623>] svc_process+0x103/0x170 [sunrpc]
> [123420.989928]  [<ffffffffa01baaaf>] nfsd+0xdf/0x150 [nfsd]
> [123420.989932]  [<ffffffffa01ba9d0>] ? nfsd_destroy+0x80/0x80 [nfsd]
> [123420.989934]  [<ffffffff810a648f>] kthread+0xcf/0xe0
> [123420.989936]  [<ffffffff810a63c0>] ? 
> kthread_create_on_node+0x140/0x140
> [123420.989939]  [<ffffffff81653318>] ret_from_fork+0x58/0x90
> [123420.989943]  [<ffffffff810a63c0>] ? 
> kthread_create_on_node+0x140/0x140
>
> I am unfamiliar with crypto.   I will be appreciated  if you could 
> give me some suggestion.
>
> Thanks,
> zhong jiang