On Wed, Jan 31, 2018 at 9:08 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > On Tue, Jan 30, 2018 at 11:59:47PM -0800, Eric Biggers wrote: >> On Fri, Dec 01, 2017 at 04:22:00PM -0800, syzbot wrote: >> > syzkaller has found reproducer for the following crash on >> > 3c1c4ddffb58b9e10b3365764fe59546130b3f32 >> > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master >> > compiler: gcc (GCC) 7.1.1 20170620 >> > .config is attached >> > Raw console output is attached. >> > C reproducer is attached >> > syzkaller reproducer is attached. See https://goo.gl/kgGztJ >> > for information about syzkaller reproducers >> > >> > >> > binder: 3087:3087 ERROR: BC_REGISTER_LOOPER called without request >> > binder: 3087:3087 ioctl c0306201 2000dfd0 returned -14 >> > ------------[ cut here ]------------ >> > kernel BUG at drivers/android/binder_alloc.c:750! >> > invalid opcode: 0000 [#1] SMP KASAN >> > Dumping ftrace buffer: >> > (ftrace buffer empty) >> > Modules linked in: >> > CPU: 0 PID: 1404 Comm: kworker/0:2 Not tainted 4.15.0-rc1+ #203 >> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> > Google 01/01/2011 >> > Workqueue: events binder_deferred_func >> > task: 0000000009b739b6 task.stack: 00000000c1d4442c >> > RIP: 0010:binder_alloc_deferred_release+0x146/0xa40 >> > drivers/android/binder_alloc.c:750 >> > RSP: 0018:ffff8801d2b16fd8 EFLAGS: 00010293 >> > RAX: ffff8801d2b08080 RBX: ffff8801d7829300 RCX: ffffffff8403b856 >> > RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801d7829330 >> > RBP: ffff8801d2b17138 R08: ffffffff8403b7d9 R09: 1ffffffff0e53001 >> > R10: ffff8801d2b16fc8 R11: ffffffff87489d60 R12: 0000000000000000 >> > R13: dffffc0000000000 R14: ffff8801d2b17110 R15: ffff8801d7829310 >> > FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 >> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> > CR2: 00000000006d00a8 CR3: 0000000005e25000 CR4: 00000000001406f0 >> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> > Call Trace: >> > binder_free_proc drivers/android/binder.c:4200 [inline] >> > binder_proc_dec_tmpref+0x2f3/0x420 drivers/android/binder.c:1833 >> > binder_deferred_release drivers/android/binder.c:4858 [inline] >> > binder_deferred_func+0xe22/0x12f0 drivers/android/binder.c:4893 >> > process_one_work+0xbfd/0x1be0 kernel/workqueue.c:2112 >> > worker_thread+0x223/0x1990 kernel/workqueue.c:2246 >> > kthread+0x37a/0x440 kernel/kthread.c:238 >> > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441 >> > Code: e8 00 40 6c fd 49 8d 7f 20 49 8d 5f f0 48 89 fa 48 c1 ea 03 42 80 3c >> > 2a 00 0f 85 84 07 00 00 49 83 7f 20 00 74 a9 e8 da 3f 6c fd <0f> 0b 48 8b 9d >> > e8 fe ff ff 44 89 a5 bc fe ff ff e8 c5 3f 6c fd >> > RIP: binder_alloc_deferred_release+0x146/0xa40 >> > drivers/android/binder_alloc.c:750 RSP: ffff8801d2b16fd8 >> > ---[ end trace 616e085d0dbf3c21 ]--- >> > Kernel panic - not syncing: Fatal exception >> > Dumping ftrace buffer: >> > (ftrace buffer empty) >> > Kernel Offset: disabled >> > Rebooting in 86400 seconds.. >> >> This crash stopped occurring in v4.15-rc3, and I verified that it was commit >> fb2c445277e which fixed it (thanks Martijn!). So, telling syzbot so that it can >> start reporting similar crashes again: >> >> #syz fix: ANDROID: binder: fix transaction leak. > > Could you change the syz fix format to include the hash in case we want > to look it up? Hi Dan, There is an unpleasant issue related to this. Some email clients (notably gmail) reflow text emails to 72/80 columns and this transformation is irreversible. So if we add hash, this increases chances of commit title (what is actually used by syzbot) being corrupted. The Reported-by tags allow precise matching of bugs to reports and back (and that's what I think now is the preferred way to doing the association as it does not require somebody to go back to the report email and attach the tag). Or I can suggest to provide commit hash on a separate line. The reflow thing is nasty, but hit us periodically. The problem that should not be there at all, but I don't see a good solution for it. Obviously requiring developers to follow some formal escaping rules for titles is not going to work either. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
