From 7514bab04e567c9408fe0facbde4277f09d5eb74 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Wed, 16 Sep 2009 04:37:27 +0000 Subject: [PATCH] af_iucv: do not call iucv_sock_kill() twice For non-accepted sockets on the accept queue, iucv_sock_kill() is called twice (in iucv_sock_close() and iucv_sock_cleanup_listen()). This typically results in a kernel oops as shown below. Remove the duplicate call to iucv_sock_kill() and set the SOCK_ZAPPED flag in iucv_sock_close() only. The iucv_sock_kill() function frees a socket only if the socket is zapped and orphaned (sk->sk_socket == NULL): - Non-accepted sockets are always orphaned and, thus, iucv_sock_kill() frees the socket twice. - For accepted sockets or sockets created with iucv_sock_create(), sk->sk_socket is initialized. This caused the first call to iucv_sock_kill() to return immediately. To free these sockets, iucv_sock_release() uses sock_orphan() before calling iucv_sock_kill(). <1>Unable to handle kernel pointer dereference at virtual kernel address 000000003edd3000 <4>Oops: 0011 [#1] PREEMPT SMP DEBUG_PAGEALLOC <4>Modules linked in: af_iucv sunrpc qeth_l3 dm_multipath dm_mod qeth vmur ccwgroup <4>CPU: 0 Not tainted 2.6.30 #4 <4>Process iucv_sock_close (pid: 2486, task: 000000003aea4340, ksp: 000000003b75bc68) <4>Krnl PSW : 0704200180000000 000003e00168e23a (iucv_sock_kill+0x2e/0xcc [af_iucv]) <4> R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3 <4>Krnl GPRS: 0000000000000000 000000003b75c000 000000003edd37f0 0000000000000001 <4> 000003e00168ec62 000000003988d960 0000000000000000 000003e0016b0608 <4> 000000003fe81b20 000000003839bb58 00000000399977f0 000000003edd37f0 <4> 000003e00168b000 000003e00168f138 000000003b75bcd0 000000003b75bc98 <4>Krnl Code: 000003e00168e22a: c0c0ffffe6eb larl %r12,3e00168b000 <4> 000003e00168e230: b90400b2 lgr %r11,%r2 <4> 000003e00168e234: e3e0f0980024 stg %r14,152(%r15) <4> >000003e00168e23a: e310225e0090 llgc %r1,606(%r2) <4> 000003e00168e240: a7110001 tmll %r1,1 <4> 000003e00168e244: a7840007 brc 8,3e00168e252 <4> 000003e00168e248: d507d00023c8 clc 0(8,%r13),968(%r2) <4> 000003e00168e24e: a7840009 brc 8,3e00168e260 <4>Call Trace: <4>([<000003e0016b0608>] afiucv_dbf+0x0/0xfffffffffffdea20 [af_iucv]) <4> [<000003e00168ec6c>] iucv_sock_close+0x130/0x368 [af_iucv] <4> [<000003e00168ef02>] iucv_sock_release+0x5e/0xe4 [af_iucv] <4> [<0000000000438e6c>] sock_release+0x44/0x104 <4> [<0000000000438f5e>] sock_close+0x32/0x50 <4> [<0000000000207898>] __fput+0xf4/0x250 <4> [<00000000002038aa>] filp_close+0x7a/0xa8 <4> [<00000000002039ba>] SyS_close+0xe2/0x148 <4> [<0000000000117c8e>] sysc_noemu+0x10/0x16 <4> [<00000042ff8deeac>] 0x42ff8deeac Signed-off-by: Hendrik Brueckner Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index a48fd2871532..c23ed4ff04c6 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -361,10 +361,9 @@ static void iucv_sock_cleanup_listen(struct sock *parent) } parent->sk_state = IUCV_CLOSED; - sock_set_flag(parent, SOCK_ZAPPED); } -/* Kill socket */ +/* Kill socket (only if zapped and orphaned) */ static void iucv_sock_kill(struct sock *sk) { if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket) @@ -426,17 +425,18 @@ static void iucv_sock_close(struct sock *sk) skb_queue_purge(&iucv->send_skb_q); skb_queue_purge(&iucv->backlog_skb_q); - - sock_set_flag(sk, SOCK_ZAPPED); break; default: sock_set_flag(sk, SOCK_ZAPPED); + /* nothing to do here */ break; } + /* mark socket for deletion by iucv_sock_kill() */ + sock_set_flag(sk, SOCK_ZAPPED); + release_sock(sk); - iucv_sock_kill(sk); } static void iucv_sock_init(struct sock *sk, struct sock *parent) -- 2.30.2