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authorOleg Nesterov <oleg@redhat.com>2010-06-04 14:14:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-06-04 15:21:45 -0700
commit485d527686850d68a0e9006dd9904f19f122485e (patch)
tree8400c646135bb4ce68f137004298e1be7fdbd913 /kernel
parentd6d03f9158516b50d0d343158e3f33bcff1e4ca5 (diff)
sys_personality: change sys_personality() to accept "unsigned int" instead of u_long
task_struct->pesonality is "unsigned int", but sys_personality() paths use "unsigned long pesonality". This means that every assignment or comparison is not right. In particular, if this argument does not fit into "unsigned int" __set_personality() changes the caller's personality and then sys_personality() returns -EINVAL. Turn this argument into "unsigned int" and avoid overflows. Obviously, this is the user-visible change, we just ignore the upper bits. But this can't break the sane application. There is another thing which can confuse the poorly written applications. User-space thinks that this syscall returns int, not long. This means that the returned value can be negative and look like the error code. But note that libc won't be confused and thus errno won't be set, and with this patch the user-space can never get -1 unless sys_personality() really fails. And, most importantly, the negative RET != -1 is only possible if that app previously called personality(RET). Pointed-out-by: Wenming Zhang <wezhang@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/exec_domain.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c
index c35452cadded..dd62f8e714ca 100644
--- a/kernel/exec_domain.c
+++ b/kernel/exec_domain.c
@@ -27,7 +27,7 @@ static struct exec_domain *exec_domains = &default_exec_domain;
static DEFINE_RWLOCK(exec_domains_lock);
-static u_long ident_map[32] = {
+static unsigned long ident_map[32] = {
0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23,
@@ -56,10 +56,10 @@ default_handler(int segment, struct pt_regs *regp)
}
static struct exec_domain *
-lookup_exec_domain(u_long personality)
+lookup_exec_domain(unsigned int personality)
{
- struct exec_domain * ep;
- u_long pers = personality(personality);
+ unsigned int pers = personality(personality);
+ struct exec_domain *ep;
read_lock(&exec_domains_lock);
for (ep = exec_domains; ep; ep = ep->next) {
@@ -70,7 +70,7 @@ lookup_exec_domain(u_long personality)
#ifdef CONFIG_MODULES
read_unlock(&exec_domains_lock);
- request_module("personality-%ld", pers);
+ request_module("personality-%d", pers);
read_lock(&exec_domains_lock);
for (ep = exec_domains; ep; ep = ep->next) {
@@ -135,7 +135,7 @@ unregister:
}
int
-__set_personality(u_long personality)
+__set_personality(unsigned int personality)
{
struct exec_domain *ep, *oep;
@@ -188,9 +188,9 @@ static int __init proc_execdomains_init(void)
module_init(proc_execdomains_init);
#endif
-SYSCALL_DEFINE1(personality, u_long, personality)
+SYSCALL_DEFINE1(personality, unsigned int, personality)
{
- u_long old = current->personality;
+ unsigned int old = current->personality;
if (personality != 0xffffffff) {
set_personality(personality);
@@ -198,7 +198,7 @@ SYSCALL_DEFINE1(personality, u_long, personality)
return -EINVAL;
}
- return (long)old;
+ return old;
}

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