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| author | Xin Long <lucien.xin@gmail.com> | 2022-04-20 16:52:41 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-04-23 22:34:17 +0100 |
| commit | 165e3e17fe8fe6a8aab319bc6e631a2e23b9a857 (patch) | |
| tree | 5dfdfa5974e8ca474c904907e86da84cdc0f94d2 /net | |
| parent | 5fd1fe4807f91ea0cca043114d929faa11bd4190 (diff) | |
| download | linux-165e3e17fe8fe6a8aab319bc6e631a2e23b9a857.tar.gz | |
sctp: check asoc strreset_chunk in sctp_generate_reconf_event
A null pointer reference issue can be triggered when the response of a
stream reconf request arrives after the timer is triggered, such as:
send Incoming SSN Reset Request --->
CPU0:
reconf timer is triggered,
go to the handler code before hold sk lock
<--- reply with Outgoing SSN Reset Request
CPU1:
process Outgoing SSN Reset Request,
and set asoc->strreset_chunk to NULL
CPU0:
continue the handler code, hold sk lock,
and try to hold asoc->strreset_chunk, crash!
In Ying Xu's testing, the call trace is:
[ ] BUG: kernel NULL pointer dereference, address: 0000000000000010
[ ] RIP: 0010:sctp_chunk_hold+0xe/0x40 [sctp]
[ ] Call Trace:
[ ] <IRQ>
[ ] sctp_sf_send_reconf+0x2c/0x100 [sctp]
[ ] sctp_do_sm+0xa4/0x220 [sctp]
[ ] sctp_generate_reconf_event+0xbd/0xe0 [sctp]
[ ] call_timer_fn+0x26/0x130
This patch is to fix it by returning from the timer handler if asoc
strreset_chunk is already set to NULL.
Fixes: 7b9438de0cd4 ("sctp: add stream reconf timer")
Reported-by: Ying Xu <yinxu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/sm_sideeffect.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index b3815b568e8e5c..463c4a58d2c36d 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -458,6 +458,10 @@ void sctp_generate_reconf_event(struct timer_list *t) goto out_unlock; } + /* This happens when the response arrives after the timer is triggered. */ + if (!asoc->strreset_chunk) + goto out_unlock; + error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF), asoc->state, asoc->ep, asoc, |