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| author | Peter Marheine <pmarheine@chromium.org> | 2020-03-19 10:25:19 +1100 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2020-03-26 02:30:48 +0000 |
| commit | eb6401aa2ccf38afadc1fc2978cbd2a6d9a7c4ce (patch) | |
| tree | dcee4a4004f1b00aae4d3e673dcae928166a54f4 | |
| parent | e37781d3dffdee742ba9ae2d80bd600a33c28b18 (diff) | |
| download | chrome-ec-eb6401aa2ccf38afadc1fc2978cbd2a6d9a7c4ce.tar.gz | |
usbc: null-check modep when entering DP mode
If a received message has an unrecognized SVID, pd_get_amode_data will
return NULL. In some cases this is normal, but any case that uses the
alternate mode data must check that it's non-NULL.
When connecting a weird display that seems to incorrectly advertise
displayport capabilities on a port but not actually support it, without
the NULL check the EC may crash or behave unpredictably when it tries to
call modep->fx->status. In practice, status was also null so it crashed
in a useful fashion.
BUG=b:151564636
TEST=connecting a problematic device no longer crashes the EC
BRANCH=None
Signed-off-by: Peter Marheine <pmarheine@chromium.org>
Change-Id: I6c552fb21556dd84f54e4228b5a7eeaab4a3bbca
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2108432
Reviewed-by: Andrew McRae <amcrae@chromium.org>
| -rw-r--r-- | common/usbc/usb_pe_drp_sm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c index 63bd28a802..9c4acb15b9 100644 --- a/common/usbc/usb_pe_drp_sm.c +++ b/common/usbc/usb_pe_drp_sm.c @@ -3848,7 +3848,7 @@ static void pe_do_port_discovery_run(int port) break; case CMD_ENTER_MODE: pe[port].vdm_cmd = CMD_DP_STATUS; - if (modep->opos) { + if (modep && modep->opos) { ret = modep->fx->status(port, pe[port].vdm_data); pe[port].vdm_data[0] |= |