On Mon, Nov 04, 2024 at 08:00:07PM -0800, Andrew Morton wrote: > On Wed, 30 Oct 2024 21:54:22 -0700 syzbot <syzbot+ccc0e1cfdb72b664f0d8@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > Hello, > > > > syzbot found the following issue on: > > Thanks. I'm suspecting some USB issue - fault injection was used to > trigger a memory allocation failure and dec_usb_memory_use_count() ended > up freeing an in-use page. Could USB folks please have a look? Andrew, I'm not sure what to look for. Can you read through usbdev_mmap() in drivers/usb/core/devio.c, along with the four short routines preceding it, and let us know if anything seems obviously wrong? Alan Stern > > HEAD commit: 850925a8133c Merge tag '9p-for-6.12-rc5' of https://github.. > > git tree: upstream > > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1346c940580000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=309bb816d40abc28 > > dashboard link: https://syzkaller.appspot.com/bug?extid=ccc0e1cfdb72b664f0d8 > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=158ab65f980000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=120e6a87980000 > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/da8019730dec/disk-850925a8.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/b1ee80babbbc/vmlinux-850925a8.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/462580e2ad54/bzImage-850925a8.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+ccc0e1cfdb72b664f0d8@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007ffede422258 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 > > RAX: ffffffffffffffda RBX: 00007ffede422280 RCX: 00007f69e1b3c569 > > RDX: 0000000002000005 RSI: 0000000000003000 RDI: 000000002001a000 > > RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000080000000 > > R10: 0000000000011012 R11: 0000000000000246 R12: 00007ffede42227c > > R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 > > </TASK> > > ------------[ cut here ]------------ > > kernel BUG at mm/page_table_check.c:157! > > Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI > > CPU: 1 UID: 0 PID: 5850 Comm: syz-executor279 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > > RIP: 0010:__page_table_check_zero+0x274/0x350 mm/page_table_check.c:157 > > Code: c1 0f 8c 39 fe ff ff 48 89 df e8 87 28 f3 ff e9 2c fe ff ff e8 dd 6a 89 ff 90 0f 0b e8 d5 6a 89 ff 90 0f 0b e8 cd 6a 89 ff 90 <0f> 0b f3 0f 1e fa 4c 89 f6 48 81 e6 ff 0f 00 00 31 ff e8 95 6f 89 > > RSP: 0018:ffffc900046bf6d8 EFLAGS: 00010293 > > RAX: ffffffff820b7fa3 RBX: dffffc0000000000 RCX: ffff88802fc13c00 > > RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801e97380c > > RBP: ffff88801e97380c R08: ffff88801e97380f R09: 1ffff11003d2e701 > > R10: dffffc0000000000 R11: ffffed1003d2e702 R12: ffff88801e9737c0 > > R13: 1ffffffff34887b4 R14: 0000000000000002 R15: 0000000000000000 > > FS: 0000555570714380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00007f69e1b92385 CR3: 0000000073ae6000 CR4: 0000000000350ef0 > > Call Trace: > > <TASK> > > page_table_check_free include/linux/page_table_check.h:41 [inline] > > free_pages_prepare mm/page_alloc.c:1109 [inline] > > free_unref_page+0xd0f/0xf20 mm/page_alloc.c:2638 > > dec_usb_memory_use_count+0x259/0x350 drivers/usb/core/devio.c:198 > > mmap_region+0x2180/0x2a30 mm/mmap.c:1574 > > do_mmap+0x8f0/0x1000 mm/mmap.c:496 > > vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588 > > ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542 > > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > > entry_SYSCALL_64_after_hwframe+0x77/0x7f
