diff mbox series

[net,5/7] sctp: add vtag check in sctp_sf_violation

Message ID 5be6dfdbfa3b618e169c5d03e2b1109310ac5938.1634730082.git.lucien.xin@gmail.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series sctp: enhancements for the verification tag | expand

Checks

Context Check Description
netdev/cover_letter success Series has a cover letter
netdev/fixes_present success Fixes tag present in non-next series
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 2 maintainers not CCed: nhorman@tuxdriver.com vyasevich@gmail.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Fixes tag looks correct
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success No static functions without inline keyword in header files

Commit Message

Xin Long Oct. 20, 2021, 11:42 a.m. UTC
sctp_sf_violation() is called when processing HEARTBEAT_ACK chunk
in cookie_wait state, and some other places are also using it.

The vtag in the chunk's sctphdr should be verified, otherwise, as
later in chunk length check, it may send abort with the existent
asoc's vtag, which can be exploited by one to cook a malicious
chunk to terminate a SCTP asoc.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/sm_statefuns.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 96a069d725e9..36328ab88bdd 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -4669,6 +4669,9 @@  enum sctp_disposition sctp_sf_violation(struct net *net,
 {
 	struct sctp_chunk *chunk = arg;
 
+	if (!sctp_vtag_verify(chunk, asoc))
+		return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
 	/* Make sure that the chunk has a valid length. */
 	if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
 		return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,