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ipc: tighten msg copy loops

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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>
This commit is contained in:
Peter Hurley 2013-04-30 19:14:37 -07:00 committed by Linus Torvalds
parent be5f4b335f
commit da085d4591
1 changed files with 11 additions and 21 deletions
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32
ipc/msgutil.c
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@ -97,18 +97,14 @@ struct msg_msg *load_msg(const void __user *src, int len)
goto out_err; goto out_err;
} }
len -= alen; for (seg = msg->next; seg != NULL; seg = seg->next) {
src = ((char __user *)src) + alen; len -= alen;
seg = msg->next; src = (char __user *)src + alen;
while (len > 0) {
alen = min(len, DATALEN_SEG); alen = min(len, DATALEN_SEG);
if (copy_from_user(seg + 1, src, alen)) { if (copy_from_user(seg + 1, src, alen)) {
err = -EFAULT; err = -EFAULT;
goto out_err; goto out_err;
} }
seg = seg->next;
len -= alen;
src = ((char __user *)src) + alen;
} }
err = security_msg_msg_alloc(msg); 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); alen = min(len, DATALEN_MSG);
memcpy(dst + 1, src + 1, alen); memcpy(dst + 1, src + 1, alen);
len -= alen; for (dst_pseg = dst->next, src_pseg = src->next;
dst_pseg = dst->next; src_pseg != NULL;
src_pseg = src->next; dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
while (len > 0) {
len -= alen;
alen = min(len, DATALEN_SEG); alen = min(len, DATALEN_SEG);
memcpy(dst_pseg + 1, src_pseg + 1, alen); 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; 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)) if (copy_to_user(dest, msg + 1, alen))
return -1; return -1;
len -= alen; for (seg = msg->next; seg != NULL; seg = seg->next) {
dest = ((char __user *)dest) + alen; len -= alen;
seg = msg->next; dest = (char __user *)dest + alen;
while (len > 0) {
alen = min(len, DATALEN_SEG); alen = min(len, DATALEN_SEG);
if (copy_to_user(dest, seg + 1, alen)) if (copy_to_user(dest, seg + 1, alen))
return -1; return -1;
len -= alen;
dest = ((char __user *)dest) + alen;
seg = seg->next;
} }
return 0; return 0;
} }