From 24b8b44780a2c53ecb738f4a1c08d114f5eda27c Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Wed, 13 Aug 2008 11:05:41 -0500 Subject: svcrdma: Fix race between svc_rdma_recvfrom thread and the dto_tasklet RDMA_READ completions are kept on a separate queue from the general I/O request queue. Since a separate lock is used to protect the RDMA_READ completion queue, a race exists between the dto_tasklet and the svc_rdma_recvfrom thread where the dto_tasklet sets the XPT_DATA bit and adds I/O to the read-completion queue. Concurrently, the recvfrom thread checks the generic queue, finds it empty and resets the XPT_DATA bit. A subsequent svc_xprt_enqueue will fail to enqueue the transport for I/O and cause the transport to "stall". The fix is to protect both lists with the same lock and set the XPT_DATA bit with this lock held. Signed-off-by: Tom Tucker Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc_rdma.h | 1 - net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 8 ++++---- net/sunrpc/xprtrdma/svc_rdma_transport.c | 5 ++--- 3 files changed, 6 insertions(+), 8 deletions(-) diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index ef2e3a2..dc05b54 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -143,7 +143,6 @@ struct svcxprt_rdma { unsigned long sc_flags; struct list_head sc_dto_q; /* DTO tasklet I/O pending Q */ struct list_head sc_read_complete_q; - spinlock_t sc_read_complete_lock; struct work_struct sc_work; }; /* sc_flags */ diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index b4b17f4..74de31a 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -443,18 +443,18 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) dprintk("svcrdma: rqstp=%p\n", rqstp); - spin_lock_bh(&rdma_xprt->sc_read_complete_lock); + spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); if (!list_empty(&rdma_xprt->sc_read_complete_q)) { ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, struct svc_rdma_op_ctxt, dto_q); list_del_init(&ctxt->dto_q); } - spin_unlock_bh(&rdma_xprt->sc_read_complete_lock); - if (ctxt) + if (ctxt) { + spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); return rdma_read_complete(rqstp, ctxt); + } - spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, struct svc_rdma_op_ctxt, diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 19ddc38..900cb69 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -359,11 +359,11 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt) if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) { struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr; BUG_ON(!read_hdr); + spin_lock_bh(&xprt->sc_rq_dto_lock); set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); - spin_lock_bh(&xprt->sc_read_complete_lock); list_add_tail(&read_hdr->dto_q, &xprt->sc_read_complete_q); - spin_unlock_bh(&xprt->sc_read_complete_lock); + spin_unlock_bh(&xprt->sc_rq_dto_lock); svc_xprt_enqueue(&xprt->sc_xprt); } svc_rdma_put_context(ctxt, 0); @@ -428,7 +428,6 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, init_waitqueue_head(&cma_xprt->sc_send_wait); spin_lock_init(&cma_xprt->sc_lock); - spin_lock_init(&cma_xprt->sc_read_complete_lock); spin_lock_init(&cma_xprt->sc_rq_dto_lock); cma_xprt->sc_ord = svcrdma_ord; -- cgit v1.1 From c228c24bf1138d4757dbe20615df655815446da3 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Thu, 21 Aug 2008 08:42:16 -0400 Subject: nfsd: fix compound state allocation error handling Move the cstate_alloc call so that if it fails, the response is setup to encode the NFS error. The out label now means that the nfsd4_compound_state has not been allocated. Signed-off-by: Andy Adamson Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4proc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 2e51ada..e5b51ff 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -867,11 +867,6 @@ nfsd4_proc_compound(struct svc_rqst *rqstp, int slack_bytes; __be32 status; - status = nfserr_resource; - cstate = cstate_alloc(); - if (cstate == NULL) - goto out; - resp->xbuf = &rqstp->rq_res; resp->p = rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len; resp->tagp = resp->p; @@ -890,6 +885,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp, if (args->minorversion > NFSD_SUPPORTED_MINOR_VERSION) goto out; + status = nfserr_resource; + cstate = cstate_alloc(); + if (cstate == NULL) + goto out; + status = nfs_ok; while (!status && resp->opcnt < args->opcnt) { op = &args->ops[resp->opcnt++]; @@ -957,9 +957,9 @@ encode_op: nfsd4_increment_op_stats(op->opnum); } + cstate_free(cstate); out: nfsd4_release_compoundargs(args); - cstate_free(cstate); dprintk("nfsv4 compound returned %d\n", ntohl(status)); return status; } -- cgit v1.1 From 27df6f25ff218072e0e879a96beeb398a79cdbc8 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Sun, 31 Aug 2008 19:25:49 +0400 Subject: sunrpc: fix possible overrun on read of /proc/sys/sunrpc/transports Vegard Nossum reported ---------------------- > I noticed that something weird is going on with /proc/sys/sunrpc/transports. > This file is generated in net/sunrpc/sysctl.c, function proc_do_xprt(). When > I "cat" this file, I get the expected output: > $ cat /proc/sys/sunrpc/transports > tcp 1048576 > udp 32768 > But I think that it does not check the length of the buffer supplied by > userspace to read(). With my original program, I found that the stack was > being overwritten by the characters above, even when the length given to > read() was just 1. David Wagner added (among other things) that copy_to_user could be probably used here. Ingo Oeser suggested to use simple_read_from_buffer() here. The conclusion is that proc_do_xprt doesn't check for userside buffer size indeed so fix this by using Ingo's suggestion. Reported-by: Vegard Nossum Signed-off-by: Cyrill Gorcunov CC: Ingo Oeser Cc: Neil Brown Cc: Chuck Lever Cc: Greg Banks Cc: Tom Tucker Signed-off-by: J. Bruce Fields --- net/sunrpc/sysctl.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/net/sunrpc/sysctl.c b/net/sunrpc/sysctl.c index 0f8c439..5231f7a 100644 --- a/net/sunrpc/sysctl.c +++ b/net/sunrpc/sysctl.c @@ -60,24 +60,14 @@ static int proc_do_xprt(ctl_table *table, int write, struct file *file, void __user *buffer, size_t *lenp, loff_t *ppos) { char tmpbuf[256]; - int len; + size_t len; + if ((*ppos && !write) || !*lenp) { *lenp = 0; return 0; } - if (write) - return -EINVAL; - else { - len = svc_print_xprts(tmpbuf, sizeof(tmpbuf)); - if (!access_ok(VERIFY_WRITE, buffer, len)) - return -EFAULT; - - if (__copy_to_user(buffer, tmpbuf, len)) - return -EFAULT; - } - *lenp -= len; - *ppos += len; - return 0; + len = svc_print_xprts(tmpbuf, sizeof(tmpbuf)); + return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len); } static int -- cgit v1.1 From 91b80969ba466ba4b915a4a1d03add8c297add3f Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 29 Aug 2008 19:18:45 -0400 Subject: nfsd: fix buffer overrun decoding NFSv4 acl The array we kmalloc() here is not large enough. Thanks to Johann Dahm and David Richter for bug report and testing. Signed-off-by: J. Bruce Fields Cc: David Richter Tested-by: Johann Dahm --- fs/nfsd/nfs4acl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c index b6ed383..54b8b41 100644 --- a/fs/nfsd/nfs4acl.c +++ b/fs/nfsd/nfs4acl.c @@ -443,7 +443,7 @@ init_state(struct posix_acl_state *state, int cnt) * enough space for either: */ alloc = sizeof(struct posix_ace_state_array) - + cnt*sizeof(struct posix_ace_state); + + cnt*sizeof(struct posix_user_ace_state); state->users = kzalloc(alloc, GFP_KERNEL); if (!state->users) return -ENOMEM; -- cgit v1.1