On Tue, Sep 17, 2019 at 4:51 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 17 Sep 2019, Dmitry Vyukov wrote: > > > On Mon, Sep 16, 2019 at 10:31 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > On Mon, 16 Sep 2019, syzbot wrote: > > > > > > > Hello, > > > > > > > > syzbot found the following crash on: > > > > > > > > HEAD commit: 014077b5 DO-NOT-SUBMIT: usb-fuzzer: main usb gadget fuzzer.. > > > > git tree: https://github.com/google/kmsan.git master > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=16a7dde1600000 > > > > kernel config: https://syzkaller.appspot.com/x/.config?x=f03c659d0830ab8d > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=e1d1a6e595adbd2458f1 > > > > compiler: clang version 9.0.0 (/home/glider/llvm/clang > > > > 80fee25776c2fb61e74c1ecb1a523375c2500b69) > > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=176303e1600000 > > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10e8f23e600000 > > > > This is probably the same problem that was fixed in the Logitech driver > > > earlier. The fix still appears to be in linux-next (commit > > > 5f9242775bb6). > > > > > > Shouldn't syzbot wait until after the merge window before running tests > > > like this? > > > > > > Merge window is a weak notion and may be not enough either (all trees > > do not necessary update at that point and syzbot does not necessary > > rebuild all of them successfully). syzbot uses another criteria: if > > you say a bug is fixed by commit X, it will wait until commit X > > reaches all of tested trees and will report the same crash signature > > again only after that. This procedure was specifically designed to not > > produce duplicate reports about the same bug. > > So either the bug wasn't really fixed, or this is another bug, or > > syzbot was given a wrong commit. > > Hmmm. Which are the "tested trees"? > > This bug (e1d1a6e595adbd2458f1) is marked as a duplicate of > 3cbe5cd105d2ad56a1df. The dashboard link says that bug was fixed by > commit "HID: logitech: Fix general protection fault caused by Logitech > driver" -- which is correct, as far as I know. > > That commit is present in linux-next, as mentioned above. As of 10:44 > EDT today, it is not present in Linus's tree, according to > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/drivers/hid/hid-lg.c > > (in fact, no commits affecting drivers/hid/hid-lg.c in that tree are > dated after 2019-07-10). > > Furthermore, according to > > https://github.com/google/kmsan/blob/master/drivers/hid/hid-lg.c?h=014077b5 > > the source code actually used by syzbot for this test doesn't have that > commit either. (BTW, is there any way to get a git log out of github? > It would be nice not to have to download the whole source file -- and > I'm not certain that this URL really does point to the version of the > file that syzbot used.) > > So what's really going on? Please see my response. This report is a different manifestation of the same Logitech bug.
