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authorPeter Hurley <peter@hurleysoftware.com>2013-04-30 19:14:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-01 08:12:57 -0700
commitda085d4591a6fe11eac2e1f659f25b655e9f2e53 (patch)
tree3f6ce1efcbf85c4a3752ef848c0fdf1e62381688 /ipc
parentbe5f4b335f6e05df1b5c24b7e7d79ff52d7b8dbc (diff)
downloadkernel-da085d4591a6fe11eac2e1f659f25b655e9f2e53.tar.gz
ipc: tighten msg copy loops
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
-rw-r--r--ipc/msgutil.c32
1 files changed, 11 insertions, 21 deletions
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index 0a5c8a95c257..b79582d461a4 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -97,18 +97,14 @@ struct msg_msg *load_msg(const void __user *src, int len)
goto out_err;
}
- len -= alen;
- src = ((char __user *)src) + alen;
- seg = msg->next;
- while (len > 0) {
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ src = (char __user *)src + alen;
alen = min(len, DATALEN_SEG);
if (copy_from_user(seg + 1, src, alen)) {
err = -EFAULT;
goto out_err;
}
- seg = seg->next;
- len -= alen;
- src = ((char __user *)src) + alen;
}
err = security_msg_msg_alloc(msg);
@@ -135,15 +131,13 @@ struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
alen = min(len, DATALEN_MSG);
memcpy(dst + 1, src + 1, alen);
- len -= alen;
- dst_pseg = dst->next;
- src_pseg = src->next;
- while (len > 0) {
+ for (dst_pseg = dst->next, src_pseg = src->next;
+ src_pseg != NULL;
+ dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
+
+ len -= alen;
alen = min(len, DATALEN_SEG);
memcpy(dst_pseg + 1, src_pseg + 1, alen);
- dst_pseg = dst_pseg->next;
- len -= alen;
- src_pseg = src_pseg->next;
}
dst->m_type = src->m_type;
@@ -166,16 +160,12 @@ int store_msg(void __user *dest, struct msg_msg *msg, int len)
if (copy_to_user(dest, msg + 1, alen))
return -1;
- len -= alen;
- dest = ((char __user *)dest) + alen;
- seg = msg->next;
- while (len > 0) {
+ for (seg = msg->next; seg != NULL; seg = seg->next) {
+ len -= alen;
+ dest = (char __user *)dest + alen;
alen = min(len, DATALEN_SEG);
if (copy_to_user(dest, seg + 1, alen))
return -1;
- len -= alen;
- dest = ((char __user *)dest) + alen;
- seg = seg->next;
}
return 0;
}