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* [PATCH v3] usb: gadget: f_fs: don't free buffer prematurely
@ 2019-03-21 21:31 fei.yang
  2019-03-22  5:36 ` Greg KH
  0 siblings, 1 reply; 3+ messages in thread
From: fei.yang @ 2019-03-21 21:31 UTC (permalink / raw)
  To: balbi, gregkh, andrzej.p, plr.vincent, fei.yang, jingx.shen,
	john.stultz, linux-usb, linux-kernel

From: Fei Yang <fei.yang@intel.com>

The following kernel panic happens due to the io_data buffer gets deallocated
before the async io is completed. Add a check for the case where io_data buffer
should be deallocated by ffs_user_copy_worker.

[   41.663334] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
[   41.672099] #PF error: [normal kernel read fault]
[   41.677356] PGD 20c974067 P4D 20c974067 PUD 20c973067 PMD 0
[   41.683687] Oops: 0000 [#1] PREEMPT SMP
[   41.687976] CPU: 1 PID: 7 Comm: kworker/u8:0 Tainted: G     U            5.0.0-quilt-2e5dc0ac-00790-gd8c79f2-dirty #2
[   41.705309] Workqueue: adb ffs_user_copy_worker
[   41.705316] RIP: 0010:__vunmap+0x2a/0xc0
[   41.705318] Code: 0f 1f 44 00 00 48 85 ff 0f 84 87 00 00 00 55 f7 c7 ff 0f 00 00 48 89 e5 41 55 41 89 f5 41 54 53 48 89 fb 75 71 e8 56 d7 ff ff <4c> 8b 60 48 4d 85 e4 74 76 48 89 df e8 25 ff ff ff 45 85 ed 74 46
[   41.705320] RSP: 0018:ffffbc3a40053df0 EFLAGS: 00010286
[   41.705322] RAX: 0000000000000000 RBX: ffffbc3a406f1000 RCX: 0000000000000000
[   41.705323] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff
[   41.705324] RBP: ffffbc3a40053e08 R08: 000000000001fb79 R09: 0000000000000037
[   41.705325] R10: ffffbc3a40053b68 R11: ffffbc3a40053cad R12: fffffffffffffff2
[   41.705326] R13: 0000000000000001 R14: 0000000000000000 R15: ffffffffffffffff
[   41.705328] FS:  0000000000000000(0000) GS:ffff9e2977a80000(0000) knlGS:0000000000000000
[   41.705329] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.705330] CR2: 0000000000000048 CR3: 000000020c994000 CR4: 00000000003406e0
[   41.705331] Call Trace:
[   41.705338]  vfree+0x50/0xb0
[   41.705341]  ffs_user_copy_worker+0xe9/0x1c0
[   41.705344]  process_one_work+0x19f/0x3e0
[   41.705348]  worker_thread+0x3f/0x3b0
[   41.829766]  kthread+0x12b/0x150
[   41.833371]  ? process_one_work+0x3e0/0x3e0
[   41.838045]  ? kthread_create_worker_on_cpu+0x70/0x70
[   41.843695]  ret_from_fork+0x3a/0x50
[   41.847689] Modules linked in: hci_uart bluetooth ecdh_generic rfkill_gpio dwc3_pci dwc3 snd_usb_audio mei_me tpm_crb snd_usbmidi_lib xhci_pci xhci_hcd mei tpm snd_hwdep cfg80211 snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core snd_hda_core videobuf2_dma_sg crlmodule
[   41.876880] CR2: 0000000000000048
[   41.880584] ---[ end trace 2bc4addff0f2e673 ]---
[   41.891346] RIP: 0010:__vunmap+0x2a/0xc0
[   41.895734] Code: 0f 1f 44 00 00 48 85 ff 0f 84 87 00 00 00 55 f7 c7 ff 0f 00 00 48 89 e5 41 55 41 89 f5 41 54 53 48 89 fb 75 71 e8 56 d7 ff ff <4c> 8b 60 48 4d 85 e4 74 76 48 89 df e8 25 ff ff ff 45 85 ed 74 46
[   41.916740] RSP: 0018:ffffbc3a40053df0 EFLAGS: 00010286
[   41.922583] RAX: 0000000000000000 RBX: ffffbc3a406f1000 RCX: 0000000000000000
[   41.930563] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff
[   41.938540] RBP: ffffbc3a40053e08 R08: 000000000001fb79 R09: 0000000000000037
[   41.946520] R10: ffffbc3a40053b68 R11: ffffbc3a40053cad R12: fffffffffffffff2
[   41.954502] R13: 0000000000000001 R14: 0000000000000000 R15: ffffffffffffffff
[   41.962482] FS:  0000000000000000(0000) GS:ffff9e2977a80000(0000) knlGS:0000000000000000
[   41.971536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   41.977960] CR2: 0000000000000048 CR3: 000000020c994000 CR4: 00000000003406e0
[   41.985930] Kernel panic - not syncing: Fatal exception
[   41.991817] Kernel Offset: 0x16000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[   42.009525] Rebooting in 10 seconds..
[   52.014376] ACPI MEMORY or I/O RESET_REG.

Fixes: 772a7a724f6 ("usb: gadget: f_fs: Allow scatter-gather buffers")
Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Tested-by: John Stultz <john.stultz@linaro.org>
---
v2: add tag: "Fixes: 772a7a724f6 ......", Reviewed-by and Tested-by.
v3: check data for NULL instead of "ret == -EIOCBQUEUED", which would be safer
    and keep the original logic intact.
---
 drivers/usb/gadget/function/f_fs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 20413c2..0bce731 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1133,7 +1133,8 @@ static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data)
 error_mutex:
 	mutex_unlock(&epfile->mutex);
 error:
-	ffs_free_buffer(io_data);
+	if (data) /* don't free if there is iocb queued */
+		ffs_free_buffer(io_data);
 	return ret;
 }
 
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v3] usb: gadget: f_fs: don't free buffer prematurely
  2019-03-21 21:31 [PATCH v3] usb: gadget: f_fs: don't free buffer prematurely fei.yang
@ 2019-03-22  5:36 ` Greg KH
  2019-03-22  6:12   ` Yang, Fei
  0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2019-03-22  5:36 UTC (permalink / raw)
  To: fei.yang
  Cc: balbi, andrzej.p, plr.vincent, jingx.shen, john.stultz,
	linux-usb, linux-kernel

On Thu, Mar 21, 2019 at 02:31:14PM -0700, fei.yang@intel.com wrote:
> From: Fei Yang <fei.yang@intel.com>
> 
> The following kernel panic happens due to the io_data buffer gets deallocated
> before the async io is completed. Add a check for the case where io_data buffer
> should be deallocated by ffs_user_copy_worker.
> 
> [   41.663334] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
> [   41.672099] #PF error: [normal kernel read fault]
> [   41.677356] PGD 20c974067 P4D 20c974067 PUD 20c973067 PMD 0
> [   41.683687] Oops: 0000 [#1] PREEMPT SMP
> [   41.687976] CPU: 1 PID: 7 Comm: kworker/u8:0 Tainted: G     U            5.0.0-quilt-2e5dc0ac-00790-gd8c79f2-dirty #2
> [   41.705309] Workqueue: adb ffs_user_copy_worker
> [   41.705316] RIP: 0010:__vunmap+0x2a/0xc0
> [   41.705318] Code: 0f 1f 44 00 00 48 85 ff 0f 84 87 00 00 00 55 f7 c7 ff 0f 00 00 48 89 e5 41 55 41 89 f5 41 54 53 48 89 fb 75 71 e8 56 d7 ff ff <4c> 8b 60 48 4d 85 e4 74 76 48 89 df e8 25 ff ff ff 45 85 ed 74 46
> [   41.705320] RSP: 0018:ffffbc3a40053df0 EFLAGS: 00010286
> [   41.705322] RAX: 0000000000000000 RBX: ffffbc3a406f1000 RCX: 0000000000000000
> [   41.705323] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff
> [   41.705324] RBP: ffffbc3a40053e08 R08: 000000000001fb79 R09: 0000000000000037
> [   41.705325] R10: ffffbc3a40053b68 R11: ffffbc3a40053cad R12: fffffffffffffff2
> [   41.705326] R13: 0000000000000001 R14: 0000000000000000 R15: ffffffffffffffff
> [   41.705328] FS:  0000000000000000(0000) GS:ffff9e2977a80000(0000) knlGS:0000000000000000
> [   41.705329] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   41.705330] CR2: 0000000000000048 CR3: 000000020c994000 CR4: 00000000003406e0
> [   41.705331] Call Trace:
> [   41.705338]  vfree+0x50/0xb0
> [   41.705341]  ffs_user_copy_worker+0xe9/0x1c0
> [   41.705344]  process_one_work+0x19f/0x3e0
> [   41.705348]  worker_thread+0x3f/0x3b0
> [   41.829766]  kthread+0x12b/0x150
> [   41.833371]  ? process_one_work+0x3e0/0x3e0
> [   41.838045]  ? kthread_create_worker_on_cpu+0x70/0x70
> [   41.843695]  ret_from_fork+0x3a/0x50
> [   41.847689] Modules linked in: hci_uart bluetooth ecdh_generic rfkill_gpio dwc3_pci dwc3 snd_usb_audio mei_me tpm_crb snd_usbmidi_lib xhci_pci xhci_hcd mei tpm snd_hwdep cfg80211 snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core snd_hda_core videobuf2_dma_sg crlmodule
> [   41.876880] CR2: 0000000000000048
> [   41.880584] ---[ end trace 2bc4addff0f2e673 ]---
> [   41.891346] RIP: 0010:__vunmap+0x2a/0xc0
> [   41.895734] Code: 0f 1f 44 00 00 48 85 ff 0f 84 87 00 00 00 55 f7 c7 ff 0f 00 00 48 89 e5 41 55 41 89 f5 41 54 53 48 89 fb 75 71 e8 56 d7 ff ff <4c> 8b 60 48 4d 85 e4 74 76 48 89 df e8 25 ff ff ff 45 85 ed 74 46
> [   41.916740] RSP: 0018:ffffbc3a40053df0 EFLAGS: 00010286
> [   41.922583] RAX: 0000000000000000 RBX: ffffbc3a406f1000 RCX: 0000000000000000
> [   41.930563] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff
> [   41.938540] RBP: ffffbc3a40053e08 R08: 000000000001fb79 R09: 0000000000000037
> [   41.946520] R10: ffffbc3a40053b68 R11: ffffbc3a40053cad R12: fffffffffffffff2
> [   41.954502] R13: 0000000000000001 R14: 0000000000000000 R15: ffffffffffffffff
> [   41.962482] FS:  0000000000000000(0000) GS:ffff9e2977a80000(0000) knlGS:0000000000000000
> [   41.971536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   41.977960] CR2: 0000000000000048 CR3: 000000020c994000 CR4: 00000000003406e0
> [   41.985930] Kernel panic - not syncing: Fatal exception
> [   41.991817] Kernel Offset: 0x16000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> [   42.009525] Rebooting in 10 seconds..
> [   52.014376] ACPI MEMORY or I/O RESET_REG.
> 
> Fixes: 772a7a724f6 ("usb: gadget: f_fs: Allow scatter-gather buffers")
> Signed-off-by: Fei Yang <fei.yang@intel.com>
> Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
> Tested-by: John Stultz <john.stultz@linaro.org>
> ---
> v2: add tag: "Fixes: 772a7a724f6 ......", Reviewed-by and Tested-by.
> v3: check data for NULL instead of "ret == -EIOCBQUEUED", which would be safer
>     and keep the original logic intact.

If it "fixes" a problem in 5.0, we should add a:
	Cc: stable <stable@vger.kernel.org>
to it as well.

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: [PATCH v3] usb: gadget: f_fs: don't free buffer prematurely
  2019-03-22  5:36 ` Greg KH
@ 2019-03-22  6:12   ` Yang, Fei
  0 siblings, 0 replies; 3+ messages in thread
From: Yang, Fei @ 2019-03-22  6:12 UTC (permalink / raw)
  To: Greg KH
  Cc: balbi, andrzej.p, plr.vincent, Shen, JingX, john.stultz,
	linux-usb, linux-kernel

>> The following kernel panic happens due to the io_data buffer gets 
>> deallocated before the async io is completed. Add a check for the case 
>> where io_data buffer should be deallocated by ffs_user_copy_worker.
>> 
>> [   41.663334] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
>> 
>> Fixes: 772a7a724f6 ("usb: gadget: f_fs: Allow scatter-gather buffers")
>> Signed-off-by: Fei Yang <fei.yang@intel.com>
>> Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
>> Tested-by: John Stultz <john.stultz@linaro.org>
>> ---
>> v2: add tag: "Fixes: 772a7a724f6 ......", Reviewed-by and Tested-by.
>> v3: check data for NULL instead of "ret == -EIOCBQUEUED", which would be safer
>>     and keep the original logic intact.
> 
> If it "fixes" a problem in 5.0, we should add a:
> 	Cc: stable <stable@vger.kernel.org>
> to it as well.
Sent [PATCH v4] with Cc: stable

> thanks,
> 
> greg k-h

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-03-22  6:12 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-03-21 21:31 [PATCH v3] usb: gadget: f_fs: don't free buffer prematurely fei.yang
2019-03-22  5:36 ` Greg KH
2019-03-22  6:12   ` Yang, Fei

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