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0070ed3d9e
There is a 16-byte memory leak inside sunrpc/auth_gss on an nfs server when a client mounts with 'sec=krb5' in a simple mount / umount loop. The leak is seen by either monitoring the kmalloc-16 slab or with kmemleak enabled unreferenced object 0xffff92e6a045f030 (size 16): comm "nfsd", pid 1096, jiffies 4294936658 (age 761.110s) hex dump (first 16 bytes): 2a 86 48 86 f7 12 01 02 02 00 00 00 00 00 00 00 *.H............. backtrace: [<000000004b2b79a7>] gssx_dec_buffer+0x79/0x90 [auth_rpcgss] [<000000002610ac1a>] gssx_dec_accept_sec_context+0x215/0x6dd [auth_rpcgss] [<000000004fd0e81d>] rpcauth_unwrap_resp+0xa9/0xe0 [sunrpc] [<000000002b099233>] call_decode+0x1e9/0x840 [sunrpc] [<00000000954fc846>] __rpc_execute+0x80/0x3f0 [sunrpc] [<00000000c83a961c>] rpc_run_task+0x10d/0x150 [sunrpc] [<000000002c2cdcd2>] rpc_call_sync+0x4d/0xa0 [sunrpc] [<000000000b74eea2>] gssp_accept_sec_context_upcall+0x196/0x470 [auth_rpcgss] [<000000003271273f>] svcauth_gss_proxy_init+0x188/0x520 [auth_rpcgss] [<000000001cf69f01>] svcauth_gss_accept+0x3a6/0xb50 [auth_rpcgss] If you map the above to code you'll see the following call chain gssx_dec_accept_sec_context gssx_dec_ctx (missing from kmemleak output) gssx_dec_buffer(xdr, &ctx->mech) Inside gssx_dec_buffer there is 'kmemdup' where we allocate memory for any gssx_buffer (buf) and store into buf->data. In the above instance, 'buf == &ctx->mech). Further up in the chain in gssp_accept_sec_context_upcall we see ctx->mech is part of a stack variable 'struct gssx_ctx rctxh'. Now later inside gssp_accept_sec_context_upcall after gssp_call, there is a number of memcpy and kfree statements, but there is no kfree(rctxh.mech.data) after the memcpy into data->mech_oid.data. With this patch applied and the same mount / unmount loop, the kmalloc-16 slab is stable and kmemleak enabled no longer shows the above backtrace. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> |
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6lowpan | ||
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802 | ||
8021q | ||
appletalk | ||
atm | ||
ax25 | ||
batman-adv | ||
bluetooth | ||
bpf | ||
bridge | ||
caif | ||
can | ||
ceph | ||
core | ||
dcb | ||
dccp | ||
decnet | ||
dns_resolver | ||
dsa | ||
ethernet | ||
hsr | ||
ieee802154 | ||
ife | ||
ipv4 | ||
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iucv | ||
kcm | ||
key | ||
l2tp | ||
l3mdev | ||
lapb | ||
llc | ||
mac80211 | ||
mac802154 | ||
mpls | ||
ncsi | ||
netfilter | ||
netlabel | ||
netlink | ||
netrom | ||
nfc | ||
nsh | ||
openvswitch | ||
packet | ||
phonet | ||
psample | ||
qrtr | ||
rds | ||
rfkill | ||
rose | ||
rxrpc | ||
sched | ||
sctp | ||
smc | ||
strparser | ||
sunrpc | ||
switchdev | ||
tipc | ||
tls | ||
unix | ||
vmw_vsock | ||
wimax | ||
wireless | ||
x25 | ||
xfrm | ||
compat.c | ||
Kconfig | ||
Makefile | ||
socket.c | ||
sysctl_net.c |