From be7a7729207797476b6666f046d765bdf9630407 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sat, 4 Jan 2020 14:15:02 +0800 Subject: [PATCH] sctp: free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY This patch is to fix a memleak caused by no place to free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY. This issue occurs when failing to process a cmd while there're still SCTP_CMD_REPLY cmds on the cmd seq with an allocated chunk in cmd->obj.chunk. So fix it by freeing cmd->obj.chunk for each SCTP_CMD_REPLY cmd left on the cmd seq when any cmd returns error. While at it, also remove 'nomem' label. Reported-by: syzbot+107c4aff5f392bf1517f@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/sctp/sm_sideeffect.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index acd737d4c0e0..834e9f82afed 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -1363,8 +1363,10 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, /* Generate an INIT ACK chunk. */ new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, 0); - if (!new_obj) - goto nomem; + if (!new_obj) { + error = -ENOMEM; + break; + } sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(new_obj)); @@ -1386,7 +1388,8 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, if (!new_obj) { if (cmd->obj.chunk) sctp_chunk_free(cmd->obj.chunk); - goto nomem; + error = -ENOMEM; + break; } sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(new_obj)); @@ -1433,8 +1436,10 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, /* Generate a SHUTDOWN chunk. */ new_obj = sctp_make_shutdown(asoc, chunk); - if (!new_obj) - goto nomem; + if (!new_obj) { + error = -ENOMEM; + break; + } sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(new_obj)); break; @@ -1770,11 +1775,17 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, break; } - if (error) + if (error) { + cmd = sctp_next_cmd(commands); + while (cmd) { + if (cmd->verb == SCTP_CMD_REPLY) + sctp_chunk_free(cmd->obj.chunk); + cmd = sctp_next_cmd(commands); + } break; + } } -out: /* If this is in response to a received chunk, wait until * we are done with the packet to open the queue so that we don't * send multiple packets in response to a single request. @@ -1789,7 +1800,4 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, sp->data_ready_signalled = 0; return error; -nomem: - error = -ENOMEM; - goto out; }