diff options
| author | Louis Scalbert <louis.scalbert@6wind.com> | 2024-09-12 09:31:49 +0200 |
|---|---|---|
| committer | Mergify <37929162+mergify[bot]@users.noreply.github.com> | 2024-09-17 12:35:28 +0000 |
| commit | 31d39e72214440b781f70d549e4c9313bc23c46e (patch) | |
| tree | b77ed2a9d052f73bf8b7f8729202ff7a6ed3d37d | |
| parent | 55aa5a3c3fa10141d7a611675a9472eb5bc634a4 (diff) | |
isisd: fix rcap tlv double-free crash
A double-free crash happens when a subTLV of the "Router Capability"
TLV is not readable and a previous "Router Capability" TLV was read.
rcap was supposed to be freed later by isis_free_tlvs() ->
free_tlv_router_cap(). In 78774bbcd5 ("isisd: add isis flex-algo lsp
advertisement"), this was not the case because rcap was not saved to
tlvs->router_cap when the function returned early because of a subTLV
length issue.
Always set tlvs->router_cap to free the memory.
Note that this patch has the consequence that in case of subTLV error,
the previously read "Router Capability" subTLVs are kept in memory.
Fixes: 49efc80d34 ("isisd: Ensure rcap is freed in error case")
Fixes: 78774bbcd5 ("isisd: add isis flex-algo lsp advertisement")
Reported-by: Iggy Frankovic <iggyfran@amazon.com>
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
(cherry picked from commit d61758140d33972c10ecbb72d0a3e528049dd8d6)
| -rw-r--r-- | isisd/isis_tlvs.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/isisd/isis_tlvs.c b/isisd/isis_tlvs.c index 59d632d170..fe0bf4ae3e 100644 --- a/isisd/isis_tlvs.c +++ b/isisd/isis_tlvs.c @@ -5270,16 +5270,17 @@ static int unpack_tlv_router_cap(enum isis_tlv_context context, return 0; } - if (tlvs->router_cap) - /* Multiple Router Capability found */ - rcap = tlvs->router_cap; - else { - /* Allocate router cap structure and initialize SR Algorithms */ - rcap = XCALLOC(MTYPE_ISIS_TLV, sizeof(struct isis_router_cap)); + if (!tlvs->router_cap) { + /* First Router Capability TLV. + * Allocate router cap structure and initialize SR Algorithms */ + tlvs->router_cap = XCALLOC(MTYPE_ISIS_TLV, + sizeof(struct isis_router_cap)); for (int i = 0; i < SR_ALGORITHM_COUNT; i++) - rcap->algo[i] = SR_ALGORITHM_UNSET; + tlvs->router_cap->algo[i] = SR_ALGORITHM_UNSET; } + rcap = tlvs->router_cap; + /* Get Router ID and Flags */ rcap->router_id.s_addr = stream_get_ipv4(s); rcap->flags = stream_getc(s); @@ -5301,7 +5302,6 @@ static int unpack_tlv_router_cap(enum isis_tlv_context context, log, indent, "WARNING: Router Capability subTLV length too large compared to expected size\n"); stream_forward_getp(s, STREAM_READABLE(s)); - XFREE(MTYPE_ISIS_TLV, rcap); return 0; } @@ -5612,7 +5612,6 @@ static int unpack_tlv_router_cap(enum isis_tlv_context context, } subtlv_len = subtlv_len - length - 2; } - tlvs->router_cap = rcap; return 0; } |