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authorXin Long <lucien.xin@gmail.com>2020-02-18 12:07:53 +0800
committerDavid S. Miller <davem@davemloft.net>2020-02-17 21:56:03 -0800
commit245709ec8be89af46ea7ef0444c9c80913999d99 (patch)
tree8bfb082154e897dafb0bd3951ec828c9558249c4 /net/sctp/sm_statefuns.c
parentnet: sched: correct flower port blocking (diff)
downloadlinux-dev-245709ec8be89af46ea7ef0444c9c80913999d99.tar.xz
linux-dev-245709ec8be89af46ea7ef0444c9c80913999d99.zip
sctp: move the format error check out of __sctp_sf_do_9_1_abort
When T2 timer is to be stopped, the asoc should also be deleted, otherwise, there will be no chance to call sctp_association_free and the asoc could last in memory forever. However, in sctp_sf_shutdown_sent_abort(), after adding the cmd SCTP_CMD_TIMER_STOP for T2 timer, it may return error due to the format error from __sctp_sf_do_9_1_abort() and miss adding SCTP_CMD_ASSOC_FAILED where the asoc will be deleted. This patch is to fix it by moving the format error check out of __sctp_sf_do_9_1_abort(), and do it before adding the cmd SCTP_CMD_TIMER_STOP for T2 timer. Thanks Hangbin for reporting this issue by the fuzz testing. v1->v2: - improve the comment in the code as Marcelo's suggestion. Fixes: 96ca468b86b0 ("sctp: check invalid value of length parameter in error cause") Reported-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--net/sctp/sm_statefuns.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 748e3b19ec1d..6a16af4b1ef6 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -170,6 +170,16 @@ static inline bool sctp_chunk_length_valid(struct sctp_chunk *chunk,
return true;
}
+/* Check for format error in an ABORT chunk */
+static inline bool sctp_err_chunk_valid(struct sctp_chunk *chunk)
+{
+ struct sctp_errhdr *err;
+
+ sctp_walk_errors(err, chunk->chunk_hdr);
+
+ return (void *)err == (void *)chunk->chunk_end;
+}
+
/**********************************************************
* These are the state functions for handling chunk events.
**********************************************************/
@@ -2255,6 +2265,9 @@ enum sctp_disposition sctp_sf_shutdown_pending_abort(
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+ if (!sctp_err_chunk_valid(chunk))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}
@@ -2298,6 +2311,9 @@ enum sctp_disposition sctp_sf_shutdown_sent_abort(
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+ if (!sctp_err_chunk_valid(chunk))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
/* Stop the T2-shutdown timer. */
sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
@@ -2565,6 +2581,9 @@ enum sctp_disposition sctp_sf_do_9_1_abort(
sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+ if (!sctp_err_chunk_valid(chunk))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
}
@@ -2582,16 +2601,8 @@ static enum sctp_disposition __sctp_sf_do_9_1_abort(
/* See if we have an error cause code in the chunk. */
len = ntohs(chunk->chunk_hdr->length);
- if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
- struct sctp_errhdr *err;
-
- sctp_walk_errors(err, chunk->chunk_hdr);
- if ((void *)err != (void *)chunk->chunk_end)
- return sctp_sf_pdiscard(net, ep, asoc, type, arg,
- commands);
-
+ if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
error = ((struct sctp_errhdr *)chunk->skb->data)->cause;
- }
sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
/* ASSOC_FAILED will DELETE_TCB. */