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authorMarian-Cristian Rotariu <marian.c.rotariu@gmail.com>2021-06-08 19:26:50 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-06-09 12:03:32 +0300
commitd00889080ab60051627dab1d85831cd9db750e2a (patch)
tree3a8645afde41dc1b51eadbd9e5be007823ed2231 /drivers/usb/dwc3
parent305f670846a31a261462577dd0b967c4fa796871 (diff)
downloadlinux-d00889080ab60051627dab1d85831cd9db750e2a.tar.xz
usb: dwc3: ep0: fix NULL pointer exception
There is no validation of the index from dwc3_wIndex_to_dep() and we might be referring a non-existing ep and trigger a NULL pointer exception. In certain configurations we might use fewer eps and the index might wrongly indicate a larger ep index than existing. By adding this validation from the patch we can actually report a wrong index back to the caller. In our usecase we are using a composite device on an older kernel, but upstream might use this fix also. Unfortunately, I cannot describe the hardware for others to reproduce the issue as it is a proprietary implementation. [ 82.958261] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a4 [ 82.966891] Mem abort info: [ 82.969663] ESR = 0x96000006 [ 82.972703] Exception class = DABT (current EL), IL = 32 bits [ 82.978603] SET = 0, FnV = 0 [ 82.981642] EA = 0, S1PTW = 0 [ 82.984765] Data abort info: [ 82.987631] ISV = 0, ISS = 0x00000006 [ 82.991449] CM = 0, WnR = 0 [ 82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc [ 83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003, pmd=0000000000000000 [ 83.009685] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 83.026433] Process irq/62-dwc3 (pid: 303, stack limit = 0x000000003985154c) [ 83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not tainted 4.19.124 #1 [ 83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO) [ 83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c [ 83.054558] lr : dwc3_ep0_interrupt+0x3b4/0xc94 ... [ 83.141788] Call trace: [ 83.144227] dwc3_ep0_handle_feature+0x414/0x43c [ 83.148823] dwc3_ep0_interrupt+0x3b4/0xc94 [ 83.181546] ---[ end trace aac6b5267d84c32f ]--- Signed-off-by: Marian-Cristian Rotariu <marian.c.rotariu@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210608162650.58426-1-marian.c.rotariu@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3')
-rw-r--r--drivers/usb/dwc3/ep0.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 8b668ef46f7f..3cd294264372 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -292,6 +292,9 @@ static struct dwc3_ep *dwc3_wIndex_to_dep(struct dwc3 *dwc, __le16 wIndex_le)
epnum |= 1;
dep = dwc->eps[epnum];
+ if (dep == NULL)
+ return NULL;
+
if (dep->flags & DWC3_EP_ENABLED)
return dep;