From: Fei Yang <[email protected]>
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.
Signed-off-by: Fei Yang <[email protected]>
---
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..47be961 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 (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
+ ffs_free_buffer(io_data);
return ret;
}
--
2.7.4
On Tue, Mar 19, 2019 at 4:25 PM <[email protected]> wrote:
>
> From: Fei Yang <[email protected]>
>
> 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.
Yay! Perfect! I was up late last night chasing this crash, but
couldn't de-thread what the problem was.
So very happy to see this patch!
I'll test it here shortly!
thanks
-john
On Tue, Mar 19, 2019 at 4:25 PM <[email protected]> wrote:
>
> From: Fei Yang <[email protected]>
>
> 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.
>
> Signed-off-by: Fei Yang <[email protected]>
Awesome! Seems to resolve the crash I was seeing!
Tested-by: John Stultz <[email protected]>
Do be sure to mark it for -stable, as I was seeing crashes all the way
back to 4.9 (and it probably affects 4.4 too).
thanks
-john
On 2019-03-20 04:55, [email protected] wrote:
> From: Fei Yang <[email protected]>
>
> 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.
[snip]
Please add tag - 'Fixes: 772a7a724f6 ("usb: gadget: f_fs: Allow
scatter-gather buffers")
> ---
> 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..47be961 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 (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
> + ffs_free_buffer(io_data);
> return ret;
> }
>> From: Fei Yang <[email protected]>
>>
>> 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.
>
> [snip]
>
> Please add tag - 'Fixes: 772a7a724f6 ("usb: gadget: f_fs: Allow scatter-gather buffers")
Sent [PATCH V2]
>> ---
>> 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..47be961 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 (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */
>> + ffs_free_buffer(io_data);
>> return ret;
>> }