From f2d47d02fd84343a3c5452daca6ed12c75618aff Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Sun, 12 Sep 2010 19:55:25 -0400 Subject: Fix null dereference in call_allocate In call_allocate we need to reach the auth in order to factor au_cslack into the allocation. As of a17c2153d2e271b0cbacae9bed83b0eaa41db7e1 "SUNRPC: Move the bound cred to struct rpc_rqst", call_allocate attempts to do this by dereferencing tk_client->cl_auth, however this is not guaranteed to be defined--cl_auth can be zero in the case of gss context destruction (see rpc_free_auth). Reorder the client state machine to bind credentials before allocating, so that we can instead reach the auth through the cred. Signed-off-by: J. Bruce Fields Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- net/sunrpc/clnt.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 2388d83b68ff..657aac630fc9 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -931,7 +931,7 @@ call_reserveresult(struct rpc_task *task) task->tk_status = 0; if (status >= 0) { if (task->tk_rqstp) { - task->tk_action = call_allocate; + task->tk_action = call_refresh; return; } @@ -972,7 +972,7 @@ call_reserveresult(struct rpc_task *task) static void call_allocate(struct rpc_task *task) { - unsigned int slack = task->tk_client->cl_auth->au_cslack; + unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack; struct rpc_rqst *req = task->tk_rqstp; struct rpc_xprt *xprt = task->tk_xprt; struct rpc_procinfo *proc = task->tk_msg.rpc_proc; @@ -980,7 +980,7 @@ call_allocate(struct rpc_task *task) dprint_status(task); task->tk_status = 0; - task->tk_action = call_refresh; + task->tk_action = call_bind; if (req->rq_buffer) return; @@ -1042,7 +1042,7 @@ call_refreshresult(struct rpc_task *task) dprint_status(task); task->tk_status = 0; - task->tk_action = call_bind; + task->tk_action = call_allocate; if (status >= 0 && rpcauth_uptodatecred(task)) return; switch (status) { -- cgit v1.2.3-59-g8ed1b From 5a67657a2e90c9e4a48518f95d4ba7777aa20fbb Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 12 Sep 2010 19:55:25 -0400 Subject: SUNRPC: Fix race corrupting rpc upcall If rpc_queue_upcall() adds a new upcall to the rpci->pipe list just after rpc_pipe_release calls rpc_purge_list(), but before it calls gss_pipe_release (as rpci->ops->release_pipe(inode)), then the latter will free a message without deleting it from the rpci->pipe list. We will be left with a freed object on the rpc->pipe list. Most frequent symptoms are kernel crashes in rpc.gssd system calls on the pipe in question. Reported-by: J. Bruce Fields Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- net/sunrpc/auth_gss/auth_gss.c | 9 +++++---- net/sunrpc/rpc_pipe.c | 6 +++--- 2 files changed, 8 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index dcfc66bab2bb..12c485982814 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -745,17 +745,18 @@ gss_pipe_release(struct inode *inode) struct rpc_inode *rpci = RPC_I(inode); struct gss_upcall_msg *gss_msg; +restart: spin_lock(&inode->i_lock); - while (!list_empty(&rpci->in_downcall)) { + list_for_each_entry(gss_msg, &rpci->in_downcall, list) { - gss_msg = list_entry(rpci->in_downcall.next, - struct gss_upcall_msg, list); + if (!list_empty(&gss_msg->msg.list)) + continue; gss_msg->msg.errno = -EPIPE; atomic_inc(&gss_msg->count); __gss_unhash_msg(gss_msg); spin_unlock(&inode->i_lock); gss_release_msg(gss_msg); - spin_lock(&inode->i_lock); + goto restart; } spin_unlock(&inode->i_lock); diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c index 95ccbcf45d3e..41a762f82630 100644 --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c @@ -48,7 +48,7 @@ static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head, return; do { msg = list_entry(head->next, struct rpc_pipe_msg, list); - list_del(&msg->list); + list_del_init(&msg->list); msg->errno = err; destroy_msg(msg); } while (!list_empty(head)); @@ -208,7 +208,7 @@ rpc_pipe_release(struct inode *inode, struct file *filp) if (msg != NULL) { spin_lock(&inode->i_lock); msg->errno = -EAGAIN; - list_del(&msg->list); + list_del_init(&msg->list); spin_unlock(&inode->i_lock); rpci->ops->destroy_msg(msg); } @@ -268,7 +268,7 @@ rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) if (res < 0 || msg->len == msg->copied) { filp->private_data = NULL; spin_lock(&inode->i_lock); - list_del(&msg->list); + list_del_init(&msg->list); spin_unlock(&inode->i_lock); rpci->ops->destroy_msg(msg); } -- cgit v1.2.3-59-g8ed1b From 006abe887c5e637d059c44310de6c92f36aded3b Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 12 Sep 2010 19:55:25 -0400 Subject: SUNRPC: Fix a race in rpc_info_open There is a race between rpc_info_open and rpc_release_client() in that nothing stops a process from opening the file after the clnt->cl_kref goes to zero. Fix this by using atomic_inc_unless_zero()... Reported-by: J. Bruce Fields Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- include/linux/sunrpc/clnt.h | 2 +- net/sunrpc/clnt.c | 26 ++++++++++++-------------- net/sunrpc/rpc_pipe.c | 14 ++++++++------ 3 files changed, 21 insertions(+), 21 deletions(-) (limited to 'net') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 569dc722a600..85f38a63f098 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -30,7 +30,7 @@ struct rpc_inode; * The high-level client handle */ struct rpc_clnt { - struct kref cl_kref; /* Number of references */ + atomic_t cl_count; /* Number of references */ struct list_head cl_clients; /* Global list of clients */ struct list_head cl_tasks; /* List of tasks */ spinlock_t cl_lock; /* spinlock */ diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 657aac630fc9..3a8f53e7ba07 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -226,7 +226,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, stru goto out_no_principal; } - kref_init(&clnt->cl_kref); + atomic_set(&clnt->cl_count, 1); err = rpc_setup_pipedir(clnt, program->pipe_dir_name); if (err < 0) @@ -390,14 +390,14 @@ rpc_clone_client(struct rpc_clnt *clnt) if (new->cl_principal == NULL) goto out_no_principal; } - kref_init(&new->cl_kref); + atomic_set(&new->cl_count, 1); err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name); if (err != 0) goto out_no_path; if (new->cl_auth) atomic_inc(&new->cl_auth->au_count); xprt_get(clnt->cl_xprt); - kref_get(&clnt->cl_kref); + atomic_inc(&clnt->cl_count); rpc_register_client(new); rpciod_up(); return new; @@ -465,10 +465,8 @@ EXPORT_SYMBOL_GPL(rpc_shutdown_client); * Free an RPC client */ static void -rpc_free_client(struct kref *kref) +rpc_free_client(struct rpc_clnt *clnt) { - struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref); - dprintk("RPC: destroying %s client for %s\n", clnt->cl_protname, clnt->cl_server); if (!IS_ERR(clnt->cl_path.dentry)) { @@ -495,12 +493,10 @@ out_free: * Free an RPC client */ static void -rpc_free_auth(struct kref *kref) +rpc_free_auth(struct rpc_clnt *clnt) { - struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref); - if (clnt->cl_auth == NULL) { - rpc_free_client(kref); + rpc_free_client(clnt); return; } @@ -509,10 +505,11 @@ rpc_free_auth(struct kref *kref) * release remaining GSS contexts. This mechanism ensures * that it can do so safely. */ - kref_init(kref); + atomic_inc(&clnt->cl_count); rpcauth_release(clnt->cl_auth); clnt->cl_auth = NULL; - kref_put(kref, rpc_free_client); + if (atomic_dec_and_test(&clnt->cl_count)) + rpc_free_client(clnt); } /* @@ -525,7 +522,8 @@ rpc_release_client(struct rpc_clnt *clnt) if (list_empty(&clnt->cl_tasks)) wake_up(&destroy_wait); - kref_put(&clnt->cl_kref, rpc_free_auth); + if (atomic_dec_and_test(&clnt->cl_count)) + rpc_free_auth(clnt); } /** @@ -588,7 +586,7 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt) if (clnt != NULL) { rpc_task_release_client(task); task->tk_client = clnt; - kref_get(&clnt->cl_kref); + atomic_inc(&clnt->cl_count); if (clnt->cl_softrtry) task->tk_flags |= RPC_TASK_SOFT; /* Add to the client's list of all tasks */ diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c index 41a762f82630..8c8eef2b8f26 100644 --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c @@ -371,21 +371,23 @@ rpc_show_info(struct seq_file *m, void *v) static int rpc_info_open(struct inode *inode, struct file *file) { - struct rpc_clnt *clnt; + struct rpc_clnt *clnt = NULL; int ret = single_open(file, rpc_show_info, NULL); if (!ret) { struct seq_file *m = file->private_data; - mutex_lock(&inode->i_mutex); - clnt = RPC_I(inode)->private; - if (clnt) { - kref_get(&clnt->cl_kref); + + spin_lock(&file->f_path.dentry->d_lock); + if (!d_unhashed(file->f_path.dentry)) + clnt = RPC_I(inode)->private; + if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) { + spin_unlock(&file->f_path.dentry->d_lock); m->private = clnt; } else { + spin_unlock(&file->f_path.dentry->d_lock); single_release(inode, file); ret = -EINVAL; } - mutex_unlock(&inode->i_mutex); } return ret; } -- cgit v1.2.3-59-g8ed1b From 55576244eba805307a2b2b6a145b8f85f8c7c124 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Sun, 12 Sep 2010 19:55:25 -0400 Subject: SUNRPC: cleanup state-machine ordering This is just a minor cleanup: net/sunrpc/clnt.c clarifies the rpc client state machine by commenting each state and by laying out the functions implementing each state in the order that each state is normally executed (in the absence of errors). The previous patch "Fix null dereference in call_allocate" changed the order of the states. Move the functions and update the comments to reflect the change. Signed-off-by: J. Bruce Fields Signed-off-by: Trond Myklebust --- net/sunrpc/clnt.c | 84 +++++++++++++++++++++++++++---------------------------- 1 file changed, 42 insertions(+), 42 deletions(-) (limited to 'net') diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 3a8f53e7ba07..fa5549079d79 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -964,7 +964,48 @@ call_reserveresult(struct rpc_task *task) } /* - * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. + * 2. Bind and/or refresh the credentials + */ +static void +call_refresh(struct rpc_task *task) +{ + dprint_status(task); + + task->tk_action = call_refreshresult; + task->tk_status = 0; + task->tk_client->cl_stats->rpcauthrefresh++; + rpcauth_refreshcred(task); +} + +/* + * 2a. Process the results of a credential refresh + */ +static void +call_refreshresult(struct rpc_task *task) +{ + int status = task->tk_status; + + dprint_status(task); + + task->tk_status = 0; + task->tk_action = call_allocate; + if (status >= 0 && rpcauth_uptodatecred(task)) + return; + switch (status) { + case -EACCES: + rpc_exit(task, -EACCES); + return; + case -ENOMEM: + rpc_exit(task, -ENOMEM); + return; + case -ETIMEDOUT: + rpc_delay(task, 3*HZ); + } + task->tk_action = call_refresh; +} + +/* + * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc. * (Note: buffer memory is freed in xprt_release). */ static void @@ -1015,47 +1056,6 @@ call_allocate(struct rpc_task *task) rpc_exit(task, -ERESTARTSYS); } -/* - * 2a. Bind and/or refresh the credentials - */ -static void -call_refresh(struct rpc_task *task) -{ - dprint_status(task); - - task->tk_action = call_refreshresult; - task->tk_status = 0; - task->tk_client->cl_stats->rpcauthrefresh++; - rpcauth_refreshcred(task); -} - -/* - * 2b. Process the results of a credential refresh - */ -static void -call_refreshresult(struct rpc_task *task) -{ - int status = task->tk_status; - - dprint_status(task); - - task->tk_status = 0; - task->tk_action = call_allocate; - if (status >= 0 && rpcauth_uptodatecred(task)) - return; - switch (status) { - case -EACCES: - rpc_exit(task, -EACCES); - return; - case -ENOMEM: - rpc_exit(task, -ENOMEM); - return; - case -ETIMEDOUT: - rpc_delay(task, 3*HZ); - } - task->tk_action = call_refresh; -} - static inline int rpc_task_need_encode(struct rpc_task *task) { -- cgit v1.2.3-59-g8ed1b From ce8477e1176389ed920550f4c925ad4a815b22d5 Mon Sep 17 00:00:00 2001 From: Bian Naimeng Date: Sun, 12 Sep 2010 19:55:25 -0400 Subject: gss:krb5 miss returning error to caller when import security context krb5 miss returning error to up layer when import security context, it may be return ok though it has failed to import security context. Signed-off-by: Bian Naimeng Signed-off-by: Trond Myklebust --- net/sunrpc/auth_gss/gss_krb5_mech.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c index 032644610524..778e5dfc5144 100644 --- a/net/sunrpc/auth_gss/gss_krb5_mech.c +++ b/net/sunrpc/auth_gss/gss_krb5_mech.c @@ -237,6 +237,7 @@ get_key(const void *p, const void *end, if (!supported_gss_krb5_enctype(alg)) { printk(KERN_WARNING "gss_kerberos_mech: unsupported " "encryption key algorithm %d\n", alg); + p = ERR_PTR(-EINVAL); goto out_err; } p = simple_get_netobj(p, end, &key); @@ -282,15 +283,19 @@ gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx) ctx->enctype = ENCTYPE_DES_CBC_RAW; ctx->gk5e = get_gss_krb5_enctype(ctx->enctype); - if (ctx->gk5e == NULL) + if (ctx->gk5e == NULL) { + p = ERR_PTR(-EINVAL); goto out_err; + } /* The downcall format was designed before we completely understood * the uses of the context fields; so it includes some stuff we * just give some minimal sanity-checking, and some we ignore * completely (like the next twenty bytes): */ - if (unlikely(p + 20 > end || p + 20 < p)) + if (unlikely(p + 20 > end || p + 20 < p)) { + p = ERR_PTR(-EFAULT); goto out_err; + } p += 20; p = simple_get_bytes(p, end, &tmp, sizeof(tmp)); if (IS_ERR(p)) @@ -619,6 +624,7 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx, if (ctx->seq_send64 != ctx->seq_send) { dprintk("%s: seq_send64 %lx, seq_send %x overflow?\n", __func__, (long unsigned)ctx->seq_send64, ctx->seq_send); + p = ERR_PTR(-EINVAL); goto out_err; } p = simple_get_bytes(p, end, &ctx->enctype, sizeof(ctx->enctype)); -- cgit v1.2.3-59-g8ed1b From 651b2933b22a0c060e6bb940c4104eb447a61f9a Mon Sep 17 00:00:00 2001 From: Bian Naimeng Date: Sun, 12 Sep 2010 19:55:26 -0400 Subject: gss:spkm3 miss returning error to caller when import security context spkm3 miss returning error to up layer when import security context, it may be return ok though it has failed to import security context. Signed-off-by: Bian Naimeng Signed-off-by: Trond Myklebust --- net/sunrpc/auth_gss/gss_spkm3_mech.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/sunrpc/auth_gss/gss_spkm3_mech.c b/net/sunrpc/auth_gss/gss_spkm3_mech.c index dc3f1f5ed865..adade3d313f2 100644 --- a/net/sunrpc/auth_gss/gss_spkm3_mech.c +++ b/net/sunrpc/auth_gss/gss_spkm3_mech.c @@ -100,6 +100,7 @@ gss_import_sec_context_spkm3(const void *p, size_t len, if (version != 1) { dprintk("RPC: unknown spkm3 token format: " "obsolete nfs-utils?\n"); + p = ERR_PTR(-EINVAL); goto out_err_free_ctx; } @@ -135,8 +136,10 @@ gss_import_sec_context_spkm3(const void *p, size_t len, if (IS_ERR(p)) goto out_err_free_intg_alg; - if (p != end) + if (p != end) { + p = ERR_PTR(-EFAULT); goto out_err_free_intg_key; + } ctx_id->internal_ctx_id = ctx; -- cgit v1.2.3-59-g8ed1b From db5fe26541b6b48460104a0d949a27cdc7786957 Mon Sep 17 00:00:00 2001 From: Miquel van Smoorenburg Date: Sun, 12 Sep 2010 19:55:26 -0400 Subject: sunrpc: increase MAX_HASHTABLE_BITS to 14 The maximum size of the authcache is now set to 1024 (10 bits), but on our server we need at least 4096 (12 bits). Increase MAX_HASHTABLE_BITS to 14. This is a maximum of 16384 entries, each containing a pointer (8 bytes on x86_64). This is exactly the limit of kmalloc() (128K). Signed-off-by: Miquel van Smoorenburg Signed-off-by: Trond Myklebust --- net/sunrpc/auth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 36cb66022a27..e9eaaf7d43c1 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -38,7 +38,7 @@ static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = { static LIST_HEAD(cred_unused); static unsigned long number_cred_unused; -#define MAX_HASHTABLE_BITS (10) +#define MAX_HASHTABLE_BITS (14) static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp) { unsigned long num; -- cgit v1.2.3-59-g8ed1b