From 32927393dc1ccd60fb2bdc05b9e8e88753761469 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Apr 2020 08:43:38 +0200 Subject: sysctl: pass kernel pointers to ->proc_handler Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig Acked-by: Andrey Ignatov Signed-off-by: Al Viro --- fs/proc/proc_sysctl.c | 47 +++++++++++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 18 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index b6f5d459b087..df2143e05c57 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -539,13 +539,13 @@ out: return err; } -static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, +static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf, size_t count, loff_t *ppos, int write) { struct inode *inode = file_inode(filp); struct ctl_table_header *head = grab_header(inode); struct ctl_table *table = PROC_I(inode)->sysctl_entry; - void *new_buf = NULL; + void *kbuf; ssize_t error; if (IS_ERR(head)) @@ -564,27 +564,38 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, if (!table->proc_handler) goto out; - error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, &count, - ppos, &new_buf); + if (write) { + kbuf = memdup_user_nul(ubuf, count); + if (IS_ERR(kbuf)) { + error = PTR_ERR(kbuf); + goto out; + } + } else { + error = -ENOMEM; + kbuf = kzalloc(count, GFP_KERNEL); + if (!kbuf) + goto out; + } + + error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count, + ppos); if (error) - goto out; + goto out_free_buf; /* careful: calling conventions are nasty here */ - if (new_buf) { - mm_segment_t old_fs; - - old_fs = get_fs(); - set_fs(KERNEL_DS); - error = table->proc_handler(table, write, (void __user *)new_buf, - &count, ppos); - set_fs(old_fs); - kfree(new_buf); - } else { - error = table->proc_handler(table, write, buf, &count, ppos); + error = table->proc_handler(table, write, kbuf, &count, ppos); + if (error) + goto out_free_buf; + + if (!write) { + error = -EFAULT; + if (copy_to_user(ubuf, kbuf, count)) + goto out_free_buf; } - if (!error) - error = count; + error = count; +out_free_buf: + kfree(kbuf); out: sysctl_head_finish(head); -- cgit v1.2.3 From 138d0be35b141e09f6b267c6ae4094318d4e4491 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 9 May 2020 10:59:10 -0700 Subject: net: bpf: Add netlink and ipv6_route bpf_iter targets This patch added netlink and ipv6_route targets, using the same seq_ops (except show() and minor changes for stop()) for /proc/net/{netlink,ipv6_route}. The net namespace for these targets are the current net namespace at file open stage, similar to /proc/net/{netlink,ipv6_route} reference counting the net namespace at seq_file open stage. Since module is not supported for now, ipv6_route is supported only if the IPV6 is built-in, i.e., not compiled as a module. The restriction can be lifted once module is properly supported for bpf_iter. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com --- fs/proc/proc_net.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'fs/proc') diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 4888c5224442..dba63b2429f0 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -98,6 +98,25 @@ static const struct proc_ops proc_net_seq_ops = { .proc_release = seq_release_net, }; +int bpf_iter_init_seq_net(void *priv_data) +{ +#ifdef CONFIG_NET_NS + struct seq_net_private *p = priv_data; + + p->net = get_net(current->nsproxy->net_ns); +#endif + return 0; +} + +void bpf_iter_fini_seq_net(void *priv_data) +{ +#ifdef CONFIG_NET_NS + struct seq_net_private *p = priv_data; + + put_net(p->net); +#endif +} + struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct seq_operations *ops, unsigned int state_size, void *data) -- cgit v1.2.3