On Mon, Aug 10, 2020 at 04:36:25AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 449dc8c9 Merge tag 'for-v5.9' of git://git.kernel.org/pub/.. > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > console output: https://syzkaller.appspot.com/x/log.txt?x=16581652900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6ef84fa8ee48e528 > dashboard link: https://syzkaller.appspot.com/bug?extid=c2c3302f9c601a4b1be2 > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16e8de34900000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1244eb62900000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c2c3302f9c601a4b1be2@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000370c7c68>] prepare_to_wait+0xb1/0x2a0 kernel/sched/wait.c:247 > WARNING: CPU: 1 PID: 340 at kernel/sched/core.c:7253 __might_sleep+0x135/0x190 kernel/sched/core.c:7253 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 340 Comm: syz-executor677 Not tainted 5.8.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xf6/0x16e lib/dump_stack.c:118 > panic+0x2aa/0x6e1 kernel/panic.c:231 > __warn.cold+0x20/0x50 kernel/panic.c:600 > report_bug+0x1bd/0x210 lib/bug.c:198 > handle_bug+0x41/0x80 arch/x86/kernel/traps.c:234 > exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254 > asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 > RIP: 0010:__might_sleep+0x135/0x190 kernel/sched/core.c:7253 > Code: 65 48 8b 1c 25 40 ef 01 00 48 8d 7b 10 48 89 fe 48 c1 ee 03 80 3c 06 00 75 2b 48 8b 73 10 48 c7 c7 e0 9e 06 86 e8 ed 12 f6 ff <0f> 0b e9 46 ff ff ff e8 1f b2 4b 00 e9 29 ff ff ff e8 15 b2 4b 00 > RSP: 0018:ffff8881cdb77a28 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: ffff8881c6458000 RCX: 0000000000000000 > RDX: ffff8881c6458000 RSI: ffffffff8129ec93 RDI: ffffed1039b6ef37 > RBP: ffffffff86fdade2 R08: 0000000000000001 R09: ffff8881db32f54f > R10: 0000000000000000 R11: 0000000030343354 R12: 00000000000001f2 > R13: 0000000000000000 R14: 0000000000000068 R15: ffffffff83c1b1aa > slab_pre_alloc_hook.constprop.0+0xea/0x200 mm/slab.h:498 > slab_alloc_node mm/slub.c:2816 [inline] > slab_alloc mm/slub.c:2900 [inline] > kmem_cache_alloc_trace+0x46/0x220 mm/slub.c:2917 > kmalloc include/linux/slab.h:554 [inline] > dummy_urb_enqueue+0x7a/0x880 drivers/usb/gadget/udc/dummy_hcd.c:1251 > usb_hcd_submit_urb+0x2b2/0x22d0 drivers/usb/core/hcd.c:1547 > usb_submit_urb+0xb4e/0x13e0 drivers/usb/core/urb.c:570 > yurex_write+0x3ea/0x820 drivers/usb/misc/yurex.c:495 The yurex driver shouldn't use GFP_KERNEL in a context where the current state isn't TASK_RUNNING. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 449dc8c9 Index: usb-devel/drivers/usb/misc/yurex.c =================================================================== --- usb-devel.orig/drivers/usb/misc/yurex.c +++ usb-devel/drivers/usb/misc/yurex.c @@ -492,7 +492,7 @@ static ssize_t yurex_write(struct file * prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE); dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__, dev->cntl_buffer[0]); - retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL); + retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC); if (retval >= 0) timeout = schedule_timeout(YUREX_WRITE_TIMEOUT); finish_wait(&dev->waitq, &wait);
