xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sctp: fix use-after-free in pr_debug statement

Browse Source 
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>
This commit is contained in:
Marcelo Ricardo Leitner
2016-01-08 11:00:54 -02:00
committed by David S. Miller
parent 366ce60315
commit 649621e3d5
2 changed files with 10 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
net/sctp/sm_sideeffect.c
View File

@@ -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.