Author: glebius
Date: Tue Oct 8 17:55:45 2019
New Revision: 353314
URL: https://svnweb.freebsd.org/changeset/base/353314
Log:
Remove epoch assertion from if_setlladdr(). Originally this function was
protected by IF_ADDR_LOCK(), which was a mutex, so that two simultaneous
if_setlladdr() can't execute. Later it was switched to IF_ADDR_RLOCK(),
likely by a mistake. Later it was switched to NET_EPOCH_ENTER(). Then I
incorrectly added NET_EPOCH_ASSERT() here.
In reality ifp->if_addr never goes away and never changes its length. So,
doing bcopy() in it is always "safe", meaning it won't dereference a wrong
pointer or write into someone's else memory. Of course doing two bcopy() in
parallel would result in a mess of two addresses, but net epoch doesn't
protect against that, neither IF_ADDR_RLOCK() did.
So for now, just remove the assertion and leave for later a proper fix.
Reported by: markj
Modified:
head/sys/net/if.c
Modified: head/sys/net/if.c
==============================================================================
--- head/sys/net/if.c Tue Oct 8 16:59:17 2019 (r353313)
+++ head/sys/net/if.c Tue Oct 8 17:55:45 2019 (r353314)
@@ -3822,26 +3822,18 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr,
struct sockaddr_dl *sdl;
struct ifaddr *ifa;
struct ifreq ifr;
- int rc;
- NET_EPOCH_ASSERT();
-
- rc = 0;
ifa = ifp->if_addr;
- if (ifa == NULL) {
- rc = EINVAL;
- goto out;
- }
+ if (ifa == NULL)
+ return (EINVAL);
sdl = (struct sockaddr_dl *)ifa->ifa_addr;
- if (sdl == NULL) {
- rc = EINVAL;
- goto out;
- }
- if (len != sdl->sdl_alen) { /* don't allow length to change */
- rc = EINVAL;
- goto out;
- }
+ if (sdl == NULL)
+ return (EINVAL);
+
+ if (len != sdl->sdl_alen) /* don't allow length to change */
+ return (EINVAL);
+
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_XETHER:
@@ -3851,8 +3843,7 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr,
bcopy(lladdr, LLADDR(sdl), len);
break;
default:
- rc = ENODEV;
- goto out;
+ return (ENODEV);
}
/*
@@ -3873,9 +3864,8 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr,
}
}
EVENTHANDLER_INVOKE(iflladdr_event, ifp);
+
return (0);
-out:
- return (rc);
}
/*
_______________________________________________
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
