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| author | Marian-Cristian Rotariu <marian.c.rotariu@gmail.com> | 2021-06-08 19:26:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-16 11:36:34 +0200 |
| commit | 60156089f07e724e4dc8483702d5e1ede4522749 (patch) | |
| tree | 72f720e8ef47e286bcbe86ca2c3d2760fe0c9aaa /drivers | |
| parent | 376b5d454d81892632b4bc197a8cb17c9a3e69be (diff) | |
| download | linux-stable-60156089f07e724e4dc8483702d5e1ede4522749.tar.gz linux-stable-60156089f07e724e4dc8483702d5e1ede4522749.tar.bz2 linux-stable-60156089f07e724e4dc8483702d5e1ede4522749.zip | |
usb: dwc3: ep0: fix NULL pointer exception
commit d00889080ab60051627dab1d85831cd9db750e2a upstream.
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')
| -rw-r--r-- | drivers/usb/dwc3/ep0.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c index 2331469f943d..bd08b53ff81d 100644 --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -328,6 +328,9 @@ 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; |