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authorMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>2018-01-02 19:44:37 -0200
committerDavid S. Miller <davem@davemloft.net>2018-01-03 11:29:42 -0500
commit79d0895140e937ba111e6420b4cd83ee75efa788 (patch)
tree6edb4a6cc1a852af40a183d6b7e7dcedaaafa046 /net/sctp
parentba77919808c6dbfc51b9ed52458c31c06197414f (diff)
downloadlinux-79d0895140e937ba111e6420b4cd83ee75efa788.tar.bz2
sctp: fix error path in sctp_stream_init
syzbot noticed a NULL pointer dereference panic in sctp_stream_free() which was caused by an incomplete error handling in sctp_stream_init(). By not clearing stream->outcnt, it made a for() in sctp_stream_free() think that it had elements to free, but not, leading to the panic. As suggested by Xin Long, this patch also simplifies the error path by moving it to the only if() that uses it. See-also: https://www.spinics.net/lists/netdev/msg473756.html See-also: https://www.spinics.net/lists/netdev/msg465024.html Reported-by: syzbot <syzkaller@googlegroups.com> Fixes: f952be79cebd ("sctp: introduce struct sctp_stream_out_ext") Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp')
-rw-r--r--net/sctp/stream.c22
1 files changed, 10 insertions, 12 deletions
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 76ea66be0bbe..524dfeb94c41 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -156,9 +156,9 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
sctp_stream_outq_migrate(stream, NULL, outcnt);
sched->sched_all(stream);
- i = sctp_stream_alloc_out(stream, outcnt, gfp);
- if (i)
- return i;
+ ret = sctp_stream_alloc_out(stream, outcnt, gfp);
+ if (ret)
+ goto out;
stream->outcnt = outcnt;
for (i = 0; i < stream->outcnt; i++)
@@ -170,19 +170,17 @@ in:
if (!incnt)
goto out;
- i = sctp_stream_alloc_in(stream, incnt, gfp);
- if (i) {
- ret = -ENOMEM;
- goto free;
+ ret = sctp_stream_alloc_in(stream, incnt, gfp);
+ if (ret) {
+ sched->free(stream);
+ kfree(stream->out);
+ stream->out = NULL;
+ stream->outcnt = 0;
+ goto out;
}
stream->incnt = incnt;
- goto out;
-free:
- sched->free(stream);
- kfree(stream->out);
- stream->out = NULL;
out:
return ret;
}