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
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parent
e4c40a8a71
commit
1e80e4f26c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=353314
30
sys/net/if.c
30
sys/net/if.c
@ -3822,26 +3822,18 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
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struct sockaddr_dl *sdl;
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struct ifaddr *ifa;
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struct ifreq ifr;
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int rc;
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NET_EPOCH_ASSERT();
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rc = 0;
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ifa = ifp->if_addr;
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if (ifa == NULL) {
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rc = EINVAL;
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goto out;
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}
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if (ifa == NULL)
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return (EINVAL);
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sdl = (struct sockaddr_dl *)ifa->ifa_addr;
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if (sdl == NULL) {
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rc = EINVAL;
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goto out;
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}
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if (len != sdl->sdl_alen) { /* don't allow length to change */
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rc = EINVAL;
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goto out;
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}
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if (sdl == NULL)
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return (EINVAL);
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if (len != sdl->sdl_alen) /* don't allow length to change */
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return (EINVAL);
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switch (ifp->if_type) {
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case IFT_ETHER:
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case IFT_XETHER:
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@ -3851,8 +3843,7 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
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bcopy(lladdr, LLADDR(sdl), len);
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break;
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default:
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rc = ENODEV;
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goto out;
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return (ENODEV);
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}
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/*
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@ -3873,9 +3864,8 @@ if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
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}
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}
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EVENTHANDLER_INVOKE(iflladdr_event, ifp);
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return (0);
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out:
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return (rc);
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}
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/*
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