From c4b8b769fa9051838d2772886ecd0ee2a926ddc3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 8 Dec 2006 02:39:55 -0800 Subject: [PATCH] [PATCH] sysctl: implement sysctl_uts_string() The problem: When using sys_sysctl we don't read the proper values for the variables exported from the uts namespace, nor do we do the proper locking. This patch introduces sysctl_uts_string which properly fetches the values and does the proper locking. Signed-off-by: Eric W. Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c8bcbfb2e069..77ea4fc386ef 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -137,6 +137,10 @@ static int parse_table(int __user *, int, void __user *, size_t __user *, static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); +static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, + void __user *oldval, size_t __user *oldlenp, + void __user *newval, size_t newlen, void **context); + #ifdef CONFIG_PROC_SYSCTL static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); @@ -258,7 +262,7 @@ static ctl_table kern_table[] = { .maxlen = sizeof(init_uts_ns.name.sysname), .mode = 0444, .proc_handler = &proc_do_uts_string, - .strategy = &sysctl_string, + .strategy = &sysctl_uts_string, }, { .ctl_name = KERN_OSRELEASE, @@ -267,7 +271,7 @@ static ctl_table kern_table[] = { .maxlen = sizeof(init_uts_ns.name.release), .mode = 0444, .proc_handler = &proc_do_uts_string, - .strategy = &sysctl_string, + .strategy = &sysctl_uts_string, }, { .ctl_name = KERN_VERSION, @@ -276,7 +280,7 @@ static ctl_table kern_table[] = { .maxlen = sizeof(init_uts_ns.name.version), .mode = 0444, .proc_handler = &proc_do_uts_string, - .strategy = &sysctl_string, + .strategy = &sysctl_uts_string, }, { .ctl_name = KERN_NODENAME, @@ -285,7 +289,7 @@ static ctl_table kern_table[] = { .maxlen = sizeof(init_uts_ns.name.nodename), .mode = 0644, .proc_handler = &proc_do_uts_string, - .strategy = &sysctl_string, + .strategy = &sysctl_uts_string, }, { .ctl_name = KERN_DOMAINNAME, @@ -294,7 +298,7 @@ static ctl_table kern_table[] = { .maxlen = sizeof(init_uts_ns.name.domainname), .mode = 0644, .proc_handler = &proc_do_uts_string, - .strategy = &sysctl_string, + .strategy = &sysctl_uts_string, }, { .ctl_name = KERN_PANIC, @@ -2598,6 +2602,23 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, return 1; } + +/* The generic string strategy routine: */ +static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, + void __user *oldval, size_t __user *oldlenp, + void __user *newval, size_t newlen, void **context) +{ + struct ctl_table uts_table; + int r, write; + write = newval && newlen; + memcpy(&uts_table, table, sizeof(uts_table)); + uts_table.data = get_uts(table, write); + r = sysctl_string(&uts_table, name, nlen, + oldval, oldlenp, newval, newlen, context); + put_uts(table, write, uts_table.data); + return r; +} + #else /* CONFIG_SYSCTL_SYSCALL */ @@ -2662,6 +2683,12 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen, return -ENOSYS; } +static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen, + void __user *oldval, size_t __user *oldlenp, + void __user *newval, size_t newlen, void **context) +{ + return -ENOSYS; +} #endif /* CONFIG_SYSCTL_SYSCALL */ /* -- 2.20.1