From 2876a34466ce382a76b9ffb34757bb48928ac743 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Tue, 18 Oct 2016 16:30:09 -0400 Subject: sunrpc: don't pass on-stack memory to sg_set_buf As of ac4e97abce9b "scatterlist: sg_set_buf() argument must be in linear mapping", sg_set_buf hits a BUG when make_checksum_v2->xdr_process_buf, among other callers, passes it memory on the stack. We only need a scatterlist to pass this to the crypto code, and it seems like overkill to require kmalloc'd memory just to encrypt a few bytes, but for now this seems the best fix. Many of these callers are in the NFS write paths, so we allocate with GFP_NOFS. It might be possible to do without allocations here entirely, but that would probably be a bigger project. Cc: Rusty Russell Signed-off-by: J. Bruce Fields --- net/sunrpc/auth_gss/auth_gss.c | 13 ++++-- net/sunrpc/auth_gss/gss_krb5_crypto.c | 82 ++++++++++++++++++++--------------- net/sunrpc/auth_gss/svcauth_gss.c | 21 ++++++--- 3 files changed, 71 insertions(+), 45 deletions(-) (limited to 'net') diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index d8bd97a5a7c9..3dfd769dc5b5 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -1616,7 +1616,7 @@ gss_validate(struct rpc_task *task, __be32 *p) { struct rpc_cred *cred = task->tk_rqstp->rq_cred; struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred); - __be32 seq; + __be32 *seq = NULL; struct kvec iov; struct xdr_buf verf_buf; struct xdr_netobj mic; @@ -1631,9 +1631,12 @@ gss_validate(struct rpc_task *task, __be32 *p) goto out_bad; if (flav != RPC_AUTH_GSS) goto out_bad; - seq = htonl(task->tk_rqstp->rq_seqno); - iov.iov_base = &seq; - iov.iov_len = sizeof(seq); + seq = kmalloc(4, GFP_NOFS); + if (!seq) + goto out_bad; + *seq = htonl(task->tk_rqstp->rq_seqno); + iov.iov_base = seq; + iov.iov_len = 4; xdr_buf_from_iov(&iov, &verf_buf); mic.data = (u8 *)p; mic.len = len; @@ -1653,11 +1656,13 @@ gss_validate(struct rpc_task *task, __be32 *p) gss_put_ctx(ctx); dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n", task->tk_pid, __func__); + kfree(seq); return p + XDR_QUADLEN(len); out_bad: gss_put_ctx(ctx); dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__, PTR_ERR(ret)); + kfree(seq); return ret; } diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c index 244245bcbbd2..90115ceefd49 100644 --- a/net/sunrpc/auth_gss/gss_krb5_crypto.c +++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c @@ -166,8 +166,8 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, unsigned int usage, struct xdr_netobj *cksumout) { struct scatterlist sg[1]; - int err; - u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + int err = -1; + u8 *checksumdata; u8 rc4salt[4]; struct crypto_ahash *md5; struct crypto_ahash *hmac_md5; @@ -187,23 +187,22 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, return GSS_S_FAILURE; } + checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS); + if (!checksumdata) + return GSS_S_FAILURE; + md5 = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(md5)) - return GSS_S_FAILURE; + goto out_free_cksum; hmac_md5 = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC); - if (IS_ERR(hmac_md5)) { - crypto_free_ahash(md5); - return GSS_S_FAILURE; - } + if (IS_ERR(hmac_md5)) + goto out_free_md5; req = ahash_request_alloc(md5, GFP_KERNEL); - if (!req) { - crypto_free_ahash(hmac_md5); - crypto_free_ahash(md5); - return GSS_S_FAILURE; - } + if (!req) + goto out_free_hmac_md5; ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); @@ -232,11 +231,8 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, ahash_request_free(req); req = ahash_request_alloc(hmac_md5, GFP_KERNEL); - if (!req) { - crypto_free_ahash(hmac_md5); - crypto_free_ahash(md5); - return GSS_S_FAILURE; - } + if (!req) + goto out_free_hmac_md5; ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); @@ -258,8 +254,12 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, cksumout->len = kctx->gk5e->cksumlength; out: ahash_request_free(req); - crypto_free_ahash(md5); +out_free_hmac_md5: crypto_free_ahash(hmac_md5); +out_free_md5: + crypto_free_ahash(md5); +out_free_cksum: + kfree(checksumdata); return err ? GSS_S_FAILURE : 0; } @@ -276,8 +276,8 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, struct crypto_ahash *tfm; struct ahash_request *req; struct scatterlist sg[1]; - int err; - u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + int err = -1; + u8 *checksumdata; unsigned int checksumlen; if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR) @@ -291,15 +291,17 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, return GSS_S_FAILURE; } + checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS); + if (checksumdata == NULL) + return GSS_S_FAILURE; + tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC); if (IS_ERR(tfm)) - return GSS_S_FAILURE; + goto out_free_cksum; req = ahash_request_alloc(tfm, GFP_KERNEL); - if (!req) { - crypto_free_ahash(tfm); - return GSS_S_FAILURE; - } + if (!req) + goto out_free_ahash; ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); @@ -349,7 +351,10 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, cksumout->len = kctx->gk5e->cksumlength; out: ahash_request_free(req); +out_free_ahash: crypto_free_ahash(tfm); +out_free_cksum: + kfree(checksumdata); return err ? GSS_S_FAILURE : 0; } @@ -368,8 +373,8 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, struct crypto_ahash *tfm; struct ahash_request *req; struct scatterlist sg[1]; - int err; - u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + int err = -1; + u8 *checksumdata; unsigned int checksumlen; if (kctx->gk5e->keyed_cksum == 0) { @@ -383,16 +388,18 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, return GSS_S_FAILURE; } + checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS); + if (!checksumdata) + return GSS_S_FAILURE; + tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC); if (IS_ERR(tfm)) - return GSS_S_FAILURE; + goto out_free_cksum; checksumlen = crypto_ahash_digestsize(tfm); req = ahash_request_alloc(tfm, GFP_KERNEL); - if (!req) { - crypto_free_ahash(tfm); - return GSS_S_FAILURE; - } + if (!req) + goto out_free_ahash; ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); @@ -433,7 +440,10 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, } out: ahash_request_free(req); +out_free_ahash: crypto_free_ahash(tfm); +out_free_cksum: + kfree(checksumdata); return err ? GSS_S_FAILURE : 0; } @@ -666,14 +676,17 @@ gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf, u32 ret; struct scatterlist sg[1]; SKCIPHER_REQUEST_ON_STACK(req, cipher); - u8 data[GSS_KRB5_MAX_BLOCKSIZE * 2]; + u8 *data; struct page **save_pages; u32 len = buf->len - offset; - if (len > ARRAY_SIZE(data)) { + if (len > GSS_KRB5_MAX_BLOCKSIZE * 2) { WARN_ON(0); return -ENOMEM; } + data = kmalloc(GSS_KRB5_MAX_BLOCKSIZE * 2, GFP_NOFS); + if (!data) + return -ENOMEM; /* * For encryption, we want to read from the cleartext @@ -708,6 +721,7 @@ gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf, ret = write_bytes_to_xdr_buf(buf, offset, data, len); out: + kfree(data); return ret; } diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index d67f7e1bc82d..45662d7f0943 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -718,30 +718,37 @@ gss_write_null_verf(struct svc_rqst *rqstp) static int gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq) { - __be32 xdr_seq; + __be32 *xdr_seq; u32 maj_stat; struct xdr_buf verf_data; struct xdr_netobj mic; __be32 *p; struct kvec iov; + int err = -1; svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS); - xdr_seq = htonl(seq); + xdr_seq = kmalloc(4, GFP_KERNEL); + if (!xdr_seq) + return -1; + *xdr_seq = htonl(seq); - iov.iov_base = &xdr_seq; - iov.iov_len = sizeof(xdr_seq); + iov.iov_base = xdr_seq; + iov.iov_len = 4; xdr_buf_from_iov(&iov, &verf_data); p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len; mic.data = (u8 *)(p + 1); maj_stat = gss_get_mic(ctx_id, &verf_data, &mic); if (maj_stat != GSS_S_COMPLETE) - return -1; + goto out; *p++ = htonl(mic.len); memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len); p += XDR_QUADLEN(mic.len); if (!xdr_ressize_check(rqstp, p)) - return -1; - return 0; + goto out; + err = 0; +out: + kfree(xdr_seq); + return err; } struct gss_domain { -- cgit v1.2.3 From 18e601d6adae5042f82d105ccd3d4498050f2ebf Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 24 Oct 2016 20:33:23 -0400 Subject: sunrpc: fix some missing rq_rbuffer assignments We've been seeing some crashes in testing that look like this: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] memcpy_orig+0x29/0x110 PGD 212ca2067 PUD 212ca3067 PMD 0 Oops: 0002 [#1] SMP Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ppdev parport_pc i2c_piix4 sg parport i2c_core virtio_balloon pcspkr acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ata_generic pata_acpi virtio_scsi 8139too ata_piix libata 8139cp mii virtio_pci floppy virtio_ring serio_raw virtio CPU: 1 PID: 1540 Comm: nfsd Not tainted 4.9.0-rc1 #39 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 task: ffff88020d7ed200 task.stack: ffff880211838000 RIP: 0010:[] [] memcpy_orig+0x29/0x110 RSP: 0018:ffff88021183bdd0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88020d7fa000 RCX: 000000f400000000 RDX: 0000000000000014 RSI: ffff880212927020 RDI: 0000000000000000 RBP: ffff88021183be30 R08: 01000000ef896996 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880211704ca8 R13: ffff88021473f000 R14: 00000000ef896996 R15: ffff880211704800 FS: 0000000000000000(0000) GS:ffff88021fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000212ca1000 CR4: 00000000000006e0 Stack: ffffffffa01ea087 ffffffff63400001 ffff880215145e00 ffff880211bacd00 ffff88021473f2b8 0000000000000004 00000000d0679d67 ffff880211bacd00 ffff88020d7fa000 ffff88021473f000 0000000000000000 ffff88020d7faa30 Call Trace: [] ? svc_tcp_recvfrom+0x5a7/0x790 [sunrpc] [] svc_recv+0xad8/0xbd0 [sunrpc] [] nfsd+0xde/0x160 [nfsd] [] ? nfsd_destroy+0x60/0x60 [nfsd] [] kthread+0xd8/0xf0 [] ret_from_fork+0x1f/0x40 [] ? kthread_park+0x60/0x60 Code: 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe 7c 35 48 83 ea 20 48 83 ea 20 4c 8b 06 4c 8b 4e 08 4c 8b 56 10 4c 8b 5e 18 48 8d 76 20 <4c> 89 07 4c 89 4f 08 4c 89 57 10 4c 89 5f 18 48 8d 7f 20 73 d4 RIP [] memcpy_orig+0x29/0x110 RSP CR2: 0000000000000000 Both Bruce and Eryu ran a bisect here and found that the problematic patch was 68778945e46 (SUNRPC: Separate buffer pointers for RPC Call and Reply messages). That patch changed rpc_xdr_encode to use a new rq_rbuffer pointer to set up the receive buffer, but didn't change all of the necessary codepaths to set it properly. In particular the backchannel setup was missing. We need to set rq_rbuffer whenever rq_buffer is set. Ensure that it is. Reviewed-by: Chuck Lever Tested-by: Chuck Lever Reported-by: Eryu Guan Tested-by: Eryu Guan Fixes: 68778945e46 "SUNRPC: Separate buffer pointers..." Reported-by: J. Bruce Fields Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 1 + net/sunrpc/xprtsock.c | 1 + 2 files changed, 2 insertions(+) (limited to 'net') diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index 2d8545c34095..fc4535ead7c2 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -182,6 +182,7 @@ xprt_rdma_bc_allocate(struct rpc_task *task) return -ENOMEM; rqst->rq_buffer = page_address(page); + rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize; return 0; } diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 0137af1c0916..e01c825bc683 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2563,6 +2563,7 @@ static int bc_malloc(struct rpc_task *task) buf->len = PAGE_SIZE; rqst->rq_buffer = buf->data; + rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize; return 0; } -- cgit v1.2.3 From 8d42629be0cb6c58a5c77cd02e47974c0e724e63 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 28 Oct 2016 22:22:33 -0400 Subject: svcrdma: backchannel cannot share a page for send and rcv buffers The underlying transport releases the page pointed to by rq_buffer during xprt_rdma_bc_send_request. When the backchannel reply arrives, rq_rbuffer then points to freed memory. Fixes: 68778945e46f ('SUNRPC: Separate buffer pointers for RPC ...') Signed-off-by: Chuck Lever Cc: Jeff Layton Signed-off-by: J. Bruce Fields --- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c index fc4535ead7c2..20027f8de129 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -177,19 +177,26 @@ xprt_rdma_bc_allocate(struct rpc_task *task) return -EINVAL; } + /* svc_rdma_sendto releases this page */ page = alloc_page(RPCRDMA_DEF_GFP); if (!page) return -ENOMEM; - rqst->rq_buffer = page_address(page); - rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize; + + rqst->rq_rbuffer = kmalloc(rqst->rq_rcvsize, RPCRDMA_DEF_GFP); + if (!rqst->rq_rbuffer) { + put_page(page); + return -ENOMEM; + } return 0; } static void xprt_rdma_bc_free(struct rpc_task *task) { - /* No-op: ctxt and page have already been freed. */ + struct rpc_rqst *rqst = task->tk_rqstp; + + kfree(rqst->rq_rbuffer); } static int -- cgit v1.2.3