diff options
author | darrenr <darrenr@FreeBSD.org> | 2001-04-06 15:52:28 +0000 |
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committer | darrenr <darrenr@FreeBSD.org> | 2001-04-06 15:52:28 +0000 |
commit | df2a765614b0751ef3c56c681930608d37287e9d (patch) | |
tree | 457d60b2d1166bfc3becb8341d6226ffcfc3ca21 /sys/netinet/ip_frag.c | |
parent | 49e5408725da3218a124fe80b74ff856b0091b24 (diff) | |
download | FreeBSD-src-df2a765614b0751ef3c56c681930608d37287e9d.zip FreeBSD-src-df2a765614b0751ef3c56c681930608d37287e9d.tar.gz |
fix security hole created by fragment cache
Diffstat (limited to 'sys/netinet/ip_frag.c')
-rw-r--r-- | sys/netinet/ip_frag.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/sys/netinet/ip_frag.c b/sys/netinet/ip_frag.c index 7e1b8be..f5548fc 100644 --- a/sys/netinet/ip_frag.c +++ b/sys/netinet/ip_frag.c @@ -141,12 +141,15 @@ fr_info_t *fin; u_int pass; ipfr_t *table[]; { - ipfr_t **fp, *fra, frag; - u_int idx; + ipfr_t **fp, *fra, frag; + u_int idx, off; if (ipfr_inuse >= IPFT_SIZE) return NULL; + if (!(fin->fin_fi.fi_fl & FI_FRAG)) + return NULL; + frag.ipfr_p = ip->ip_p; idx = ip->ip_p; frag.ipfr_id = ip->ip_id; @@ -200,7 +203,10 @@ ipfr_t *table[]; /* * Compute the offset of the expected start of the next packet. */ - fra->ipfr_off = (ip->ip_off & IP_OFFMASK) + (fin->fin_dlen >> 3); + off = ip->ip_off & IP_OFFMASK; + if (!off) + fra->ipfr_seen0 = 1; + fra->ipfr_off = off + (fin->fin_dlen >> 3); ATOMIC_INCL(ipfr_stats.ifs_new); ATOMIC_INC32(ipfr_inuse); return fra; @@ -256,6 +262,9 @@ ipfr_t *table[]; ipfr_t *f, frag; u_int idx; + if (!(fin->fin_fi.fi_fl & FI_FRAG)) + return NULL; + /* * For fragments, we record protocol, packet id, TOS and both IP#'s * (these should all be the same for all fragments of a packet). @@ -283,6 +292,19 @@ ipfr_t *table[]; IPFR_CMPSZ)) { u_short atoff, off; + /* + * XXX - We really need to be guarding against the + * retransmission of (src,dst,id,offset-range) here + * because a fragmented packet is never resent with + * the same IP ID#. + */ + off = ip->ip_off & IP_OFFMASK; + if (f->ipfr_seen0) { + if (!off || (fin->fin_fi.fi_fl & FI_SHORT)) + continue; + } else if (!off) + f->ipfr_seen0 = 1; + if (f != table[idx]) { /* * move fragment info. to the top of the list @@ -295,7 +317,6 @@ ipfr_t *table[]; f->ipfr_prev = NULL; table[idx] = f; } - off = ip->ip_off & IP_OFFMASK; atoff = off + (fin->fin_dlen >> 3); /* * If we've follwed the fragments, and this is the |