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| author | Xin Long <lucien.xin@gmail.com> | 2022-04-20 16:52:41 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-12 12:17:07 +0200 |
| commit | 227414256351f0601f2570cfbed2b12be316c1e8 (patch) | |
| tree | 58ac3ebda39d138edfc28a571d1e2a0643f8f38f | |
| parent | 7d3c0c1276d549b98442025c0249881b1a674e4c (diff) | |
| download | linux-227414256351f0601f2570cfbed2b12be316c1e8.tar.gz linux-227414256351f0601f2570cfbed2b12be316c1e8.tar.bz2 linux-227414256351f0601f2570cfbed2b12be316c1e8.zip | |
sctp: check asoc strreset_chunk in sctp_generate_reconf_event
[ Upstream commit 165e3e17fe8fe6a8aab319bc6e631a2e23b9a857 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 1a1128355d86..169819263c0b 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -456,6 +456,10 @@ void sctp_generate_reconf_event(unsigned long data) 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, |