On Fri, 4 Feb 2022, Hillf Danton wrote: > > ------------[ cut here ]------------ > > kernel BUG at drivers/hid/hidraw.c:335! > > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > > CPU: 1 PID: 5036 Comm: syz-executor223 Not tainted 5.17.0-rc2-syzkaller-00039-g9f7fb8de5d9b-dirty #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:drop_ref+0x375/0x3e0 drivers/hid/hidraw.c:335 > > Code: fb e9 a9 fd ff ff 48 89 ef 89 74 24 04 e8 43 61 04 fb 8b 74 24 04 e9 64 fd ff ff e8 a5 61 04 fb e9 13 fd ff ff e8 8b 1f bd fa <0f> 0b 48 89 df e8 31 61 04 fb e9 5a fe ff ff 48 89 de 48 c7 c7 a0 > > RSP: 0018:ffffc90005da7ac8 EFLAGS: 00010293 > > RAX: 0000000000000000 RBX: ffff88801deef9b0 RCX: 0000000000000000 > > RDX: ffff888072660000 RSI: ffffffff86bb4ef5 RDI: ffffffff90869f60 > > RBP: ffff88801deef900 R08: 0000000000000000 R09: ffffffff8ffbda7f > > R10: ffffffff86bb4cd2 R11: 0000000000000000 R12: 0000000000000001 > > R13: ffff88801deef908 R14: ffff88807f1e98e0 R15: ffff88807f1e8000 > > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > > CR2: 00007f229e36a600 CR3: 0000000079b38000 CR4: 00000000003506e0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > <TASK> > > hidraw_disconnect+0x48/0x60 drivers/hid/hidraw.c:600 > > hid_disconnect+0x130/0x1a0 drivers/hid/hid-core.c:2036 > > hid_hw_stop drivers/hid/hid-core.c:2079 [inline] > > hid_device_remove+0x15d/0x200 drivers/hid/hid-core.c:2411 > > __device_release_driver+0x3bd/0x700 drivers/base/dd.c:1204 > > device_release_driver_internal drivers/base/dd.c:1237 [inline] > > device_release_driver+0x26/0x40 drivers/base/dd.c:1260 > > bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529 > > device_del+0x502/0xd50 drivers/base/core.c:3592 > > hid_remove_device drivers/hid/hid-core.c:2578 [inline] > > hid_destroy_device+0xe1/0x150 drivers/hid/hid-core.c:2597 > > uhid_dev_destroy drivers/hid/uhid.c:587 [inline] > > uhid_char_release+0xed/0x210 drivers/hid/uhid.c:663 > > __fput+0x286/0x9f0 fs/file_table.c:311 > > task_work_run+0xdd/0x1a0 kernel/task_work.c:164 > > exit_task_work include/linux/task_work.h:32 [inline] > > do_exit+0xb29/0x2a30 kernel/exit.c:806 > > do_group_exit+0xd2/0x2f0 kernel/exit.c:935 > > __do_sys_exit_group kernel/exit.c:946 [inline] > > __se_sys_exit_group kernel/exit.c:944 [inline] > > __ia32_sys_exit_group+0x3a/0x50 kernel/exit.c:944 > > do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] > > __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 > > do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 > > entry_SYSENTER_compat_after_hwframe+0x4d/0x5c > > RIP: 0023:0xf7ee8549 > > Code: Unable to access opcode bytes at RIP 0xf7ee851f. > > RSP: 002b:00000000ff8aaf4c EFLAGS: 00000292 ORIG_RAX: 00000000000000fc > > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 > > RDX: 00000000f7f94fa0 RSI: 00000000f7f953b8 RDI: 00000000f7f953b8 > > RBP: 00000000f7f95928 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > </TASK> > > Modules linked in: > > ---[ end trace 0000000000000000 ]--- > > RIP: 0010:drop_ref+0x375/0x3e0 drivers/hid/hidraw.c:335 > > Code: fb e9 a9 fd ff ff 48 89 ef 89 74 24 04 e8 43 61 04 fb 8b 74 24 04 e9 64 fd ff ff e8 a5 61 04 fb e9 13 fd ff ff e8 8b 1f bd fa <0f> 0b 48 89 df e8 31 61 04 fb e9 5a fe ff ff 48 89 de 48 c7 c7 a0 > > RSP: 0018:ffffc90005da7ac8 EFLAGS: 00010293 > > RAX: 0000000000000000 RBX: ffff88801deef9b0 RCX: 0000000000000000 > > RDX: ffff888072660000 RSI: ffffffff86bb4ef5 RDI: ffffffff90869f60 > > RBP: ffff88801deef900 R08: 0000000000000000 R09: ffffffff8ffbda7f > > R10: ffffffff86bb4cd2 R11: 0000000000000000 R12: 0000000000000001 > > R13: ffff88801deef908 R14: ffff88807f1e98e0 R15: ffff88807f1e8000 > > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > > CR2: 00007f64971d1018 CR3: 000000007f5e0000 CR4: 00000000003506f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > > > > Tested on: > > > > commit: 9f7fb8de Merge tag 'spi-fix-v5.17-rc2' of git://git.ke.. > > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > > console output: https://syzkaller.appspot.com/x/log.txt?x=15e029cc700000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=b4a89edfcc8f7c74 > > dashboard link: https://syzkaller.appspot.com/bug?extid=953a33deaf38c66a915e > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > userspace arch: i386 > > patch: https://syzkaller.appspot.com/x/patch.diff?x=12571934700000 > > This proves what Dmitry explained, given minor M, hidrawA == hidraw_table[M] > was freed with someone dangling on the hidrawA->list because of zero open > count, then another opener put hidrawB in hidraw_table[M]. > > TBH no evidence of leak in open count spotted, see what will come up with > parallel openers disabled. > > Hillf > > #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ 9f7fb8de5d9b > > --- a/drivers/hid/hidraw.c > +++ b/drivers/hid/hidraw.c > @@ -272,7 +272,7 @@ static int hidraw_open(struct inode *ino > goto out; > } > > - down_read(&minors_rwsem); > + down_write(&minors_rwsem); > if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { > err = -ENODEV; > goto out_unlock; > @@ -301,7 +301,7 @@ static int hidraw_open(struct inode *ino > spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags); > file->private_data = list; > out_unlock: > - up_read(&minors_rwsem); > + up_write(&minors_rwsem); > out: > if (err < 0) > kfree(list); > @@ -332,6 +332,7 @@ static void drop_ref(struct hidraw *hidr > if (!hidraw->open) { > if (!hidraw->exist) { > hidraw_table[hidraw->minor] = NULL; > + BUG_ON(!list_empty(&hidraw->list)); > kfree(hidraw); > } else { > /* close device for last reader */ Hillf, could you please submit this properly with a full changelog, signed-off-by: line, etc? Thanks, -- Jiri Kosina SUSE Labs
