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| author | Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> | 2016-01-08 11:00:54 -0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-01-11 17:13:01 -0500 |
| commit | 649621e3d54439ae232d726d7beef295d3887a68 (patch) | |
| tree | e8229276e251856aab325ce510d22cd51a35e3f0 /net/sctp/sm_sideeffect.c | |
| parent | 366ce60315292a579b8ceae2777102e1954a2024 (diff) | |
| download | linux-649621e3d54439ae232d726d7beef295d3887a68.tar.bz2 | |
sctp: fix use-after-free in pr_debug statement
Dmitry Vyukov reported a use-after-free in the code expanded by the
macro debug_post_sfx, which is caused by the use of the asoc pointer
after it was freed within sctp_side_effect() scope.
This patch fixes it by allowing sctp_side_effect to clear that asoc
pointer when the TCB is freed.
As Vlad explained, we also have to cover the SCTP_DISPOSITION_ABORT case
because it will trigger DELETE_TCB too on that same loop.
Also, there were places issuing SCTP_CMD_INIT_FAILED and ASSOC_FAILED
but returning SCTP_DISPOSITION_CONSUME, which would fool the scheme
above. Fix it by returning SCTP_DISPOSITION_ABORT instead.
The macro is already prepared to handle such NULL pointer.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sctp/sm_sideeffect.c')
| -rw-r--r-- | net/sctp/sm_sideeffect.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 6098d4c42fa9..be23d5c2074f 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -63,7 +63,7 @@ static int sctp_cmd_interpreter(sctp_event_t event_type, static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, sctp_state_t state, struct sctp_endpoint *ep, - struct sctp_association *asoc, + struct sctp_association **asoc, void *event_arg, sctp_disposition_t status, sctp_cmd_seq_t *commands, @@ -1123,7 +1123,7 @@ int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, debug_post_sfn(); error = sctp_side_effects(event_type, subtype, state, - ep, asoc, event_arg, status, + ep, &asoc, event_arg, status, &commands, gfp); debug_post_sfx(); @@ -1136,7 +1136,7 @@ int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, sctp_state_t state, struct sctp_endpoint *ep, - struct sctp_association *asoc, + struct sctp_association **asoc, void *event_arg, sctp_disposition_t status, sctp_cmd_seq_t *commands, @@ -1151,7 +1151,7 @@ static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, * disposition SCTP_DISPOSITION_CONSUME. */ if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state, - ep, asoc, + ep, *asoc, event_arg, status, commands, gfp))) goto bail; @@ -1174,11 +1174,12 @@ static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, break; case SCTP_DISPOSITION_DELETE_TCB: + case SCTP_DISPOSITION_ABORT: /* This should now be a command. */ + *asoc = NULL; break; case SCTP_DISPOSITION_CONSUME: - case SCTP_DISPOSITION_ABORT: /* * We should no longer have much work to do here as the * real work has been done as explicit commands above. |